Bulletin of the American Physical Society
68th Annual Meeting of the APS Division of Fluid Dynamics
Volume 60, Number 21
Sunday–Tuesday, November 22–24, 2015; Boston, Massachusetts
Session KP1: Poster Session 
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Room: Exhibit Hall D (Technical Poster Display Area) 

KP1.00001: ACOUSTICS 

KP1.00002: Exploration of the Use of Triple Correlation in the Analysis of Acoustic Data Genevieve Starke, Jacques Lewalle Jet noise is a longstanding environmental problem. To better understand the underlying mechanisms, acoustic data from several microphones in the far field of a Ma = 0.6 round jet are being analyzed. Currently, crosscorrelation is being used to compare two signals and find the largest peak value of the correlation coefficient. This indicates the best match for the same information reaching two microphones at different times; it also gives the lag of the sound events which is helpful in the location of the sources of the events. This is traditionally done with pairs of signals, either with entire signals or with eventlevel short excerpts. Then, multiple signals require the matching of the results of various pairwise correlations. Here, we explore triple correlation as a way to make this process more efficient. Triple correlation uses a sliding method, adjusting the signals by time steps and graphing the mean of the product of the result. One of the signals is selected as a ‘base’, and the two other signals are shifted relative to the base signal. The result gives a graph giving the lags of both signals in relation to the base signal. The triple correlation algorithm is being tested on simple signals and will be applied to experimental data. We will report on the applicatio [Preview Abstract] 

KP1.00003: Addressing the likelihood of cumulative nonlinear distortion in supersonic jet noise using the effective Gol'dberg number Woutijn J. Baars, Charles E. Tinney, Mark F. Hamilton When replicating fullscale jets by way of subscale experiments, it is routine to aim for aerodynamic similarity; this is achieved by matching the jet's geometry, Mach number, temperature ratio and Reynolds number. We here compute the effective Gol'dberg number ($\Lambda$) to assess acoustic similarity for supersonic jetswhether the wave propagation obeys by linear or nonlinear theory. Cumulative nonlinear wave distortion may only appear when the jet flow and ambient surround are sufficient incubators for distortion. Noticeably, the imperative conditions for sustaining this distortion do not scale following aerodynamic similarity laws. A method for computing $\Lambda$ encompasses a ray tube situated along the Mach angle where the sound is not only most intense, but advances from undergoing cylindrical to sphericaldecay in its pressure amplitude. Hence, values of $\Lambda$ are computed separately for the cylindrically and spherically spreading regions, for a plethora of experimental databases. The findings demonstrate how for subscale jets, cumulative nonlinear distortion may be present in the region of cylindrical spreading alone. It is revealed that nonlinear distortion is likely to sustain in the region of spherical pressure decay when fullscale jets are concerned. [Preview Abstract] 

KP1.00004: AERODYNAMICS 

KP1.00005: ABSTRACT WITHDRAWN 

KP1.00006: Large eddy simulation of a high speed train geometry under crosswind with an adaptive lattice Boltzmann method Ralf Deiterding, Moritz M. Fragner Numerical investigations in order to determine the forces induced by side wind onto a train geometry are generally not sufficiently accurate to be used as a predictive tool for regulatory safety assessment. Especially for larger yaw angles, the turbulent crosswind flow is characterized by highly instationary behavior, driven primarily by vortex shedding on the roof and underside geometric details, i.e., the bogie and wheel systems. While industrytypical Reynoldsaveraged turbulence models are not well suited for this scenario, better results are obtained when large eddy simulation (LES) techniques are applied. Here, we employ a recently selfdeveloped weakly compressible lattice Boltzmann method (LBM) with Smagorinsky LES model on hierarchically adaptive blockstructured Cartesian meshes. Using a train frontcar of 1:25 scale at yaw angle 30$^{\circ}$ and $\mathrm{Re}=250,000$ as main test case, we compare the LBM results with incompressible large eddy and detached eddy simulations on unstructured boundarylayer type meshes using the OpenFOAM package. It is found that time averaged force and moment predictions from our LBM code compare better to available wind tunnel data, while mesh adaptation and explicit nature of the LBM approach reduce the computational costs considerably. [Preview Abstract] 

KP1.00007: The Ultimate Flow Controlled Wind Turbine Blade Airfoil Avraham Seifert, Danny Dolgopyat, Ori Friedland, Lior Shig Active flow control is being studied as an enabling technology to enhance and maintain high efficiency of wind turbine blades also with contaminated surface and unsteady winds as well as at offdesign operating conditions. The study is focused on a 25{\%} thick airfoil (DU91W2250) suitable for the mid blade radius location. Initially a clean airfoil was fabricated and tested, as well as compared to XFoil predictions. From these experiments, the evolution of the separation location was identified. Five locations for installing active flow control actuators are available on this airfoil. It uses both Piezo fluidic (``Synthetic jets'') and the Suction and Oscillatory Blowing (SaOB) actuators. Then we evaluate both actuation concepts overall energy efficiency and efficacy in controlling boundary layer separation. Since efficient actuation is to be found at low amplitudes when placed close to separation location, distributed actuation is used. Following the completion of the baseline studies the study has focused on the airfoil instrumentation and extensive wind tunnel testing over a Reynolds number range of 0.2 to 1.5 Million. Sample results will be presented and outline for continued study will be discussed. [Preview Abstract] 

KP1.00008: Design of Shrouded Airborne Wind Turbine {\&} CFD Analysis Faiqa Anbreen, Reza Toossi The focus is to design a shrouded airborne wind turbine, capable to generate 70 kW to propel a leisure boat. The idea of designing an airborne turbine is to take the advantage of different velocity layers in the atmosphere. The blades have been designed using NREL S826 airfoil, which has coefficient of lift C$_{L}$ of 1.4 at angle of attack, 6$^{\circ}$. The value selected for C$_{P}$ is 0.8. The rotor diameter is 7.4 m. The balloon (shroud) has convergingdiverging nozzle design, to increase the mass flow rate through the rotor. The ratio of inlet area to throat area, A$_{i}$/A$_{t}$ is 1.31 and exit area to throat area, A$_{e}$/A$_{t}$ is1.15. The Solidworks model has been analyzed numerically using CFD. The software used is StarCCM$+$. The Unsteady Reynolds Averaged Navier Stokes Simulation (URANS) K$\varepsilon $ model has been selected, to study the physical properties of the flow, with emphasis on the performance of the turbine. Stress analysis has been done using Nastran. From the simulations, the torque generated by the turbine is approximately 800Nm and angular velocity is 21 rad/s. [Preview Abstract] 

KP1.00009: Toward Affordable, TheoryandSimulationInspired, Models for Realistic Wind Turbine Aerodynamics and Noise Foluso Ladeinde, Ken Alabi, Wenhai Li The problem of generating design data for the operation of a farm of wind turbines for clean energy production is quite complicated, if properly done. Potential flow theories provide some models, but these are not suitable for the massive aerodynamic separation and turbulence that characterize many realistic wind turbine applications. Procedures, such as computational fluid dynamics (CFD), which can potentially resolve some of the accuracy problems with the purely theoretical approach, are quite expensive to use, and often prohibit realtime design and control. In our work, we seek affordable and acceptablyaccurate models derived from the foregoing approaches. The simulation used in our study is based on highfidelity CFD, meaning that we use highorder (compactscheme based), mostly largeeddy simulation methods, with due regards for the proper treatment of the stochastic inflow turbulence data. Progress on the project described herein will be presented. [Preview Abstract] 

KP1.00010: ASTROPHYSICAL FLUID DYNAMICS . [Preview Abstract] 

KP1.00011: Implications of new planet discoveries to our knowledge of solar system Victor Christianto, Florentin Smarandache In recent years a number of new planetoids have been reported, in particular by M. Brown and his team. While new planet discoveries have been reported from time to time, known as exoplanets, nonetheless discovery of new planetoids in the solar system are very interesting, because they are found after a long period of silence after Pluto finding, around seventy years ago. Therefore, it seems interesting to find out implications of this discovery to our knowledge of solar system, in particular in the context of quantization of celestial system. [Preview Abstract] 

KP1.00012: Simultaneous PLIF/PIV measurements for a singlemode inclined interface Mohammad Mohaghar, David Reilly, John Carter, Jacob Mcfarland, Devesh Ranjan The Shock Tube and Advanced Mixing Laboratory (STAML) at Georgia Institute of Technology is using a newly established inclined shock tube facility to study an inclined interface perturbation. This facility allows for simultaneous characterization of density and velocity fields by employing highresolution, fullfield Planar LaserInduced Fluorescence (PLIF) and Particle Image Velocimetry (PIV), respectively. The incident shock strength of Mach 1.55 was used to impulsively accelerate a N$_{\mathrm{2}}$Acetone mixture over CO$_{\mathrm{2}}$ inclined interface with an Atwood number of 0.23 and an 80$^{\mathrm{o}}$ angle of inclination. This angle of inclination results in a linear perturbation as defined by the amplitudetowavelength ratio ($\eta $/$\lambda =$0.097). The development of the turbulent mixing layer for both pre and postreshock is determined by measuring several quantities, including two BHR model parameters: density selfcorrelation and turbulent mass flux. [Preview Abstract] 

KP1.00013: BIOLOGICAL FLUID DYNAMICS 

KP1.00014: RANS and LES simulations of the airflow through nasal cavities Giacomo Lamberti The prediction of detailed flow patterns in nasal cavities using computational fluid dynamics (CFD) can provide essential information on the potential relationship between patientspecific geometrical characteristics and health problems. The longterm goal of the OpenNOSE project is to develop a reliable opensource computational tool based on the OpenFOAM CFD toolbox that can assist surgeons in their daily practice. The objective of this study was to investigate the effect of the turbulence model and boundary conditions on simulations of the airflow in nasal cavities. The geometry, including paranasal sinuses, was reconstructed from a carefully selected CT scan, and RANS and LES simulations were carried out for steady inspiration and expiration. At a flow rate near 20 l/min, the flow is laminar in most of the domain. During the inspiration phase, turbulence develops in nasopharynx and oropharynx regions; during the expiration phase, another vortical region is observed down the nostrils. A comparison between different boundary conditions suggests the use of a total pressure condition, or alternatively a uniform velocity, at the inlet and outlet. In future work the same geometry will be used for setting up a laboratory experiment, intended to crossvalidate the numerical results. [Preview Abstract] 

KP1.00015: Turbulence effects on hemolysis by revisiting experiments with LES computations Mesude Ozturk, Edgar O'Rear, Dimitrios Papavassiliou Determining mechanically stimulated red blood cell trauma as a function of turbulence properties is required to design prosthetic heart devices [1]. Because blood is typically exposed to turbulence in such devices, the design of prosthetic heart devices depends on determining the effect of turbulent stresses on hemolysis [2,3]. While turbulent stresses increase hemolysis when cells are exposed to them [3], turbulent flow characteristics in the vicinity of lysed blood cells, and the mechanism of cell damage remains uncertain [2,3]. In this work, LES computations are used to investigate the effect of turbulent eddy structure on cell damage. The flow was simulated for classic Couette and capillary tube experiments [3, 4], in order to examine the relation between hemolysis turbulence properties related to the dissipation of turbulent kinetic energy. The hypothesis tested is that eddies that are close in size with the erythrocytes are the ones that are responsible for hemolysis, rather than Reynolds stresses or viscous stresses. We define extensive measures, like the eddy areas for small eddies comparable to the size of the red blood cells, to provide a more general understanding of the mechanical cause of blood trauma. References 1. Quinlan NJ, Dooley PN.. Ann Biomed Eng. 2007;35:134756. 2. Aziz A, et al. Ann Biomed Eng. 2007;35:210820. 3. Kameneva MV, et al., ASAIO, 2004;50:41823. 4. Sutera SP, Mehrjardi MH., Biophysical J., 1975;15:110. [Preview Abstract] 

KP1.00016: Influence of substrate micropatterning on biofilm growth Stephan Koehler, Yiwei Li, BiFeng Liu Liu, David Weitz We culture triple reporter Bacillus Subtilis biofilm on micropatterned agar substrates. We track the biofilm development in terms of size, thickness, shape, and phenotype expression. For a tiling composed of elevated rectangles, we observe the biofilm develops an oval shape or triangular shape depending on the rectangle's aspect ratio and orientation. The motile cells are primarily located in the valleys between the rectangles and the matrix producing cells are mostly located on the rectangles. Wrinkles form at the edges of the elevated surfaces, and upon merging form channels centered on the elevated surface. After a few days, the sporeforming cells appear at the periphery. Since biofilms in nature grow on irregular surfaces, our work may provide insight into the complex patterns observed. [Preview Abstract] 

KP1.00017: The effect of low accurate vesicle suspensions on observables Bryan Quaife, George Biros Vesicle suspensions, which are experimental and numerical proxies for red blood cells and other biomembranes, are ubiquitous in various applications such as biological flows. The governing equations for vesicle suspensions include several challenging aspects such as nonlocal interactions, an inextensibility and incompressibility constraint, and a fourthorder arclength derivative. The simulation of vesicle suspensions can be accelerated by introducing several approximations. For instance, vesicles can be discretized at a coarse resolution, the accuracy of the nonlocal interactions can be reduced, and the area and length of the vesicle can be locally corrected. First I will describe several algorithms that are required to maintain stability at low accuracies. Then, I will discuss the effect these approximations have on several observables, such as the statistics of the velocity field. [Preview Abstract] 

KP1.00018: MOVED TO R35.010 

KP1.00019: Water Transport through CohesionTension in Porous Structures Srinivas Kosaraju The predominant theory to explain water transport through plant xylem is the cohesiontension theory. According to the theory, negative pressure is created due to water evaporation through millions of microscopic capillary pores from tree leaves. The negative pressures are large enough to lift water hundreds of feet against gravity. In an attempt to replicate the process, multiple structures with varying porosity are tested to create negative pressures through water evaporation. The negative pressure created is used to support a water column. The current research is aimed to create artificial leaves using porous structures and be able to transport water in high rise buildings using renewable energy sources such as solar power. [Preview Abstract] 

KP1.00020: Flow distributions and spatial correlations in human brain capillary networks Sylvie Lorthois, Myriam Peyrounette, Anne Larue, Tanguy Le Borgne The vascular system of the human brain cortex is composed of a space filling meshlike capillary network connected upstream and downstream to branched quasifractal arterioles and venules. The distribution of blood flow rates in these networks may affect the efficiency of oxygen transfer processes. Here, we investigate the distribution and correlation properties of blood flow velocities from numerical simulations in large 3D human intracortical vascular network (~10000 segments) obtained from an anatomical database. In each segment, flow is solved from a 1D nonlinear model taking account of the complex rheological properties of blood flow in microcirculation to deduce blood pressure, blood flow and red blood cell volume fraction distributions throughout the network. The network structural complexity is found to impart broad and spatially correlated Lagrangian velocity distributions, leading to power law transit time distributions. The origins of this behavior (existence of velocity correlations in capillary networks, influence of the coupling with the feeding arterioles and draining veins, topological disorder, complex blood rheology) are studied by comparison with results obtained in various model capillary networks of controlled disorder. [Preview Abstract] 

KP1.00021: Mild coarctation of the aorta: to touch or not to touch the patient? Zahra KeshavarzMotamed, Amanda Randles, Farhad Rikhtegar Nezami, Ramon Partida, Kenta Nakamura, Pedro V. Staziaki, Brian Ghoshhajra, Ami Bhatt, Elazer R. Edelman Coarctation of the aorta (COA) is an aortic obstruction. A peaktopeak transcoarctation pressure gradient (P$_{K}$dP) of greater than 20 mmHg warns severe COA and the need for interventional/surgical repair. The optimal method and timing of intervention remain uncertain especially for mild COA (P$_{K}$dP \textless 20 mmHg); even it is unclear if mild COA should be treated at all. Although it was recently suggested that treatment strategies for mild COA may need to be redefined as transcatheter interventions emerge, benefits of such interventions are unclear. We investigated the effects of transcatheter interventions on the aorta and left ventricle (LV) hemodynamics in 11 patients with mild COA using a developed computational fluid dynamics and lumped parameter modeling framework along with particle image velocimetry and clinical measurements. Such interventions can improve aortic hemodynamics to some extent (e.g., timeaveraged wall shear stress and kinetic energy were reduced by about 20{\%}). However there is no concomitant effect on the LV hemodynamics (e.g., stroke work and LV pressure were reduced by only less than 4{\%}). Our computational approach can effectively predict clinical conditions. Herein one must question intervention for mild COA, as it has limited utility in reducing myocardial strain. [Preview Abstract] 

KP1.00022: A projection scheme for velocity field reconstruction in the left ventricle Sarah Frank, Juan Carlos Del Alamo, Shawn C Shadden Color Doppler ultrasound is a convenient and relatively inexpensive tool that can be used to measure the radial flow field inside the heart. Recently, this technology has been extended to produce a twocomponent flow field on the apical long axis plane of the left ventricle [1]. Specifically, the azimuthal component is reconstructed by solving a planar continuity equation based on the assumption that throughplane divergence is negligible. In this work we present an alternative scheme that solves for the eigenmodes of the left ventricle, projects available data onto these modes, and solves for the optimal projection using leastsquares methods. Alternative implementations of this approach are considered and compared. To make comparisons, we applied this method to the radial component only of threedirectional MRI velocity data in the longaxis plane. Subsequently, the reconstructed velocity fields were compared to the original full MRI velocity field. [1] Garcia D, Del Alamo JC, Tanne D, Yotti R, Cortina C, Bertrand E, Antoranz JC, PerezDavid E, Rieu R, FernandezAviles F, Bermejo J (2010) Twodimensional intraventricular flow mapping by digital processing conventional colorDoppler echocardiography images. IEEE Trans Med Imaging 29 (10):17011713. [Preview Abstract] 

KP1.00023: Particle Deposition in Human Lungs due to Varying CrossSectional Ellipticity of Left and Right Main Bronchi Steven Roth, Jessica Oakes, Shawn Shadden Particle deposition in the human lungs can occur with every breathe. Airbourne particles can range from toxic constituents (e.g. tobacco smoke and air pollution) to aerosolized particles designed for drug treatment (e.g. insulin to treat diabetes). The effect of various realistic airway geometries on complex flow structures, and thus particle deposition sites, has yet to be extensively investigated using computational fluid dynamics (CFD). In this work, we created an imagebased geometric airway model of the human lung and performed CFD simulations by employing multidomain methods (Oakes et al. (2014), Annals of Biomedical Engineering, 42: 899914). Following the flow simulations, Lagrangian particle tracking was used to study the effect of crosssectional shape on deposition sites in the conducting airways. From a single human lung model, the crosssectional ellipticity (the ratio of major and minor diameters) of the left and right main bronchi was varied systematically from 2:1 to 1:1. The influence of the airway ellipticity on the surrounding flow field and particle deposition was determined. [Preview Abstract] 

KP1.00024: Optimal branching designs in respiratory systems Keunhwan Park, Wonjung Kim, HoYoung Kim In nature, the size of the flow channels systematically decreases with multiple generations of branching, and a mother branch is ultimately divided into numerous terminal daughters. One important feature of branching designs is an increase in the total crosssectional area along with generation, which provide more time and area for mass transfer at the terminal branches. However, the expansion of the total crosssectional area can be costly due to the maintenance of redundant branches or the additional viscous resistance. Accordingly, we expect to find optimal designs in natural branching systems. Here we present two examples of branching designs in respiratory systems: fish gills and human lung airways. Fish gills consist of filaments with wellordered lamellar structures. By developing a mathematical model of oxygen transfer rate as a function of the dimensions of fish gills, we demonstrate that the interlamellar distance has been optimized to maximize the oxygen transfer rate. Using the same framework, we examine the diameter reduction ratio in human lung airways, which branch by dichotomy with a systematic reduction of their diameters. Our mathematical model for oxygen transport in the airways enables us to unveil the design principle of human lung airways. [Preview Abstract] 

KP1.00025: The effect of wing stroke and aspect ratio on the force generation a compliant membrane flapping wing Cosima Schunk, Sharon M. Swartz, Kenneth S. Breuer Aspect ratio is one parameter used in efforts to predict a bat species' flight performance based on wing shape. Bats with high aspect ratio wings are expected to have superior lifttodrag ratios and therefore to fly faster or be able to sustain longer flights. In contrast, bats with lower aspect ratio wings are usually thought to exhibit higher maneuverability. These assumptions are often based on fixedwing aerodynamic theory, and do not take the wide variation in flapping kinematics observed in bats into account. To examine the influence of different stroke patterns, we measure lift and drag of highly compliant membrane wings with different batrelevant aspect ratios. A two degree of freedom shoulder joint allows for independent control of flapping amplitude and wing sweep. We test five models with the same variations of stroke patterns, flapping frequencies, and wind speeds. [Preview Abstract] 

KP1.00026: An Integrated Simulation of a WingBody Combination for a Hovering \textit{Drosophila} Mehmet Sahin, Ezgi Dilek, Belkis Erzincanli The parallel largescale unstructured finite volume method based on an Arbitrary LagrangianEulerian (ALE) formulation has been applied in order to investigate the near wake structure of a hovering \textit{Drosophila} flight. DISTENE MeshGemsHexa algorithm based on the octree method is used to generate the all hexahedral mesh for the wingbody combination. The mesh deformation algorithm is based on the indirect radial basis function (RBF) method at each time level while avoiding remeshing in order to enhance numerical robustness. The largescale numerical simulations are carried out for a flapping \textit{Drosophila} in hover flight. The $\lambda_{2}$criterion proposed by Jeong and Hussain (1995) is used for investigating the time variation of the Eulerian coherent structures in the near wake. In addition, the Lagrangian coherent structures is also investigated using finitetime Lyapunov exponents (FTLE) fields. The present simulations reveal highly detailed near wake topology for a hovering \textit{Drosophila}. This is very useful in terms of understanding physics in biological flights which can provide a very useful tool for designing bioinspired MAVs. [Preview Abstract] 

KP1.00027: ABSTRACT WITHDRAWN 

KP1.00028: Aeromechanics of the Spider Cricket Jump: How to Jump 60+ Times Your Body Length and Still Land on Your Feet Emily Palmer, Nicolas Deshler, David Gorman, Catarina Neves, Rajat Mittal Flapping, gliding, running, crawling and swimming have all been studied extensively in the past and have served as a source of inspiration for engineering designs. In the current project, we explore a mode of locomotion that straddles ground and air: jumping. The subject of our study is among the most proficient of longjumpers in Nature: the spider cricket of the family Rhaphidophoridae, which can jump more than 60 times its body length. Despite jumping this immense distance, these crickets usually land on their feet, indicating an ability to control their posture during ``flight.'' We employ highspeed videogrammetry, to examine the jumps and to track the crickets’ posture and appendage orientation throughout their jumps. Simple aerodynamic models are developed to predict the aerodynamic forces and moment on the crickets during `flight`. The analysis shows that these wingless insects employ carefully controlled and coordinated positioning of the limbs during flight so as to increase jump distance and to stabilize body posture during flight. The principles distilled from this study could serve as an inspiration for small jumping robots that can traverse complex terrains. [Preview Abstract] 

KP1.00029: Development of a New Method for Platelet Function Test and Its Shearing Condition in Microfludic System Hoyoon Lee, Gyehyu Kim, Seawhan Choi, Sehyun Shin Platelet is a crucial blood cell on hemostasis. As platelet exposed to high shear stress, it can be activated showing morphological and functional changes to stop bleeding. When platelet is abnormal, there is high risk of cardiovascular diseases. Thus, quick and precise assay for platelet function is important in clinical treatment. In this study, we design a microfluidic system, which can test platelet function exposed with the stimulation of shear and agonists. The microfluidic system consists of three parts: 1) a shear mechanism with rotating stirrer; 2) multiple microchannels to flow samples and to stop; 3) camerainterfaced migration distance(MD) analyzing system. When sheared blood is driven by pressure through the microchannel, shearactivated platelets adhere to a collagencoated surface, causing blood flow to significantly slow and eventually stop. As the microstirrer speed increases, MD decreases exponentially at first, but it increases beyond a critical rpm after all. These results are coincident with data measured by FACS flowcytometry. These results imply that the present system could quantitatively measure the degree of activation, aggregation and adhesion of platelets and that blood MD is potent index for measuring the sheardependence of platelet function. [Preview Abstract] 

KP1.00030: Visualization of pulsatile flow for magnetic nanoparticle based therapies Andrew Wentzel, Philip Yecko Pulsatile flow of blood through branched, curved, stenosed, dilated or otherwise perturbed vessels is more complex than flow through a straight, uniform and rigid tube. In some magnetic hyperthermia and magnetic chemotherapies, localized regions of magnetic nanoparticle laden fluid are deliberately formed in blood vessels and held in place by magnetic fields. The effect of localized magnetic fluid regions on blood flow and the effect of the pulsatile blood flow on such magnetic fluid regions are poorly understood and difficult to examine {\it in vivo} or by numerical simulation. We present a laboratory model that facilitates both dye tracer and particle imaging velocimetry (PIV) studies of pulsatile flow of water through semiflexible tubes in the presence of localized magnetic fluid regions. Results on the visualization of flows over a range of Reynolds and Womersley numbers and for several different (waterbased) ferrofluids are compared for straight and curved vessels and for different magnetic localization strategies. These results can guide the design of improved magnetic cancer therapies. [Preview Abstract] 

KP1.00031: BOUNDARY LAYERS 

KP1.00032: Progress Towards an LES Wall Model Including Unresolved Roughness Kyle Craft, Andrew Redman, Kurt Aikens Wall models used in large eddy simulations (LES) are often based on theories for hydraulically smooth walls. While this is reasonable for many applications, there are also many where the impact of surface roughness is important. A previously developed wall model\footnote{K.~M.~Aikens, ``Highfidelity large eddy simulation for supersonic jet noise prediction,'' Ph.D. thesis, Purdue University, 2014.} has been used primarily for jet engine aeroacoustics. However, jet simulations have not accurately captured thick initial shear layers found in some experimental data.\footnote{R.~W.~Powers, C.W.~Kuo and D.~K.~McLaughlin, AIAA Paper No.~20132186, 2013 (unpublished).} This may partly be due to nozzle wall roughness used in the experiments to promote turbulent boundary layers. As a result, the wall model is extended to include the effects of unresolved wall roughness through appropriate alterations to the loglaw. The methodology is tested for incompressible flat plate boundary layers with different surface roughness. Correct trends are noted for the impact of surface roughness on the velocity profile. However, velocity deficit profiles and the Reynolds stresses do not collapse as well as expected. Possible reasons for the discrepancies as well as future work will be presented. [Preview Abstract] 

KP1.00033: A Test of the Validity of Inviscid WallModeled LES Andrew Redman, Kyle Craft, Kurt Aikens \hyphenpenalty=1000 Computational expense is one of the main deterrents to more widespread use of large eddy simulations (LES). As such, it is important to reduce computational costs whenever possible. In this vein, it may be reasonable to assume that high Reynolds number flows with turbulent boundary layers are inviscid when using a wall model. This assumption relies on the grid being too coarse to resolve either the viscous length scales in the outer flow or those near walls. We are not aware of other studies that have suggested or examined the validity of this approach. The inviscid wallmodeled LES assumption is tested here for supersonic flow over a flat plate on three different grids. Inviscid and viscous results are compared to those of another wallmodeled LES as well as experimental data  the results appear promising. Furthermore, the inviscid assumption reduces simulation costs by about 25\% and 39\% for supersonic and subsonic flows, respectively, with the current LES application.\footnote{K.~M.~Aikens, ``Highfidelity large eddy simulation for supersonic jet noise prediction,'' Ph.D. thesis, Purdue University, 2014.} Recommendations are presented as are future areas of research. [Preview Abstract] 

KP1.00034: MicroScale Simulation of Water Transport in Porous Media Coupled with Phase Change Sahand Etemad, Arash Behrang, Peyman Mohammadmoradi, Hossein Hejazi, Apostolos Kantzas Subpore scale modeling of flow in porous media is gaining momentum. The concept of Digital Core Analysis deals with measurements of virtual core and the purpose of such modeling is to replace conventional and special core analysis when the latter are not feasible. Single phase flow phenomena are nowadays fairly easy to model given a good representation of the porous medium by its digital counterpart. Two phase flow modeling has proven more difficult to represent due to the complexities introduced by the insert of interfaces. These problems were at least partially overcome by the implementation of the ``Volume of Fluid'' method. OpenFOAM is the CFD package of choice in this work. The aforementioned approach is currently being extended in the modeling of phase change within a porous medium. Surface roughness is introduced by the incorporation of wedges of variable density and amplitude on the pore surface. A further introduced complication is that the individual grains are of different mineralogy and thus of different wettability. The problem of steam condensation in such media is addressed. It is observed that steam condenses first in the smallest of wedges, which act a nucleation sites. Water spreads on waterwet surfaces. Snapoff is observed in several cases leading to temporary trapping of vapor. Grid size effects are also addressed. The application of this modeling effort is the condensation of steam in thermal recovery methods. [Preview Abstract] 

KP1.00035: The scaling laws for the energycontaining range of secondorder structure functions above a dense vegetation canopy Ying Pan, Marcelo Chamecki Theoretical and experimental results show that the energycontaining range of secondorder streamwise spatial structure function within the logarithmic layer of moderate and highReynoldsnumber wall turbulence is scaled by the dissipation length scale. We extend these scaling laws for turbulent flows above a dense vegetation canopy, where the structure of turbulence is more analogous to a free shear layer than a wall boundary layer. The imbalance between production and dissipation of turbulent kinetic energy (TKE) within the canopy shear layer is much greater than that within the logarithmic layer of wall turbulence. For evaluation of the scaling laws, we use largeeddy simulation (LES) results that well reproduce field experimental data of the secondorder streamwise temporal structure function of filtered velocity above the canopy. Within the shear layer above the canopy, LES results of secondorder streamwise spatial structure function of filtered velocity are correctly scaled by the dissipation length scale, confirming the theoretical extension of the scaling laws. This work is a preliminary step towards universal scaling laws for turbulent shear flows. [Preview Abstract] 

KP1.00036: BUBBLES 

KP1.00037: Investigation of Manipulation Technique of Microbubbles Using Focused Ultrasound. Taichi Osaki, Kazuhito Inoue, Yoichiro Matsumoto, Shu Takagi, Takashi Azuma, Mitsuhisa Ichiyanagi Recently, it has been thought that the application of ultrasound and microbubbles(MB) is utility to the medical field. Should MB be manipulated contactlessly, it will contribute to the mechanism investigation on the drug delivery system using MB as drug carrier. However no technique has yet to be established that can trap MB at any desired position, manipulate them along any desired path. Accordingly in this research, we investigated whether it was possible to trap MB at desired position, manipulate them along desired paths through experiments aimed at the development of MB manipulation tools that utilize ultrasound. Moreover, we analyzed the microbubble behaviors in ultrasound field. Bubbles in the ultrasound wave field are subjected to the primary Bjerknes force. Our method aimed that MB are trapped at the antinode or the node and manipulated with moving the antinode or node. We fabricated a concave transducer which radiates focused ultrasound and used sonazoid as MB and they were trapped at the focus as a cluster. The transducer moves its own position to move its focus and manipulate MB. Besides, we observed the trapped cluster with several incident frequencies. MB were trapped and manipulated along a locus of alphabet ?M? about 100 µm. From this result, it is implied that MB can be manipulated along any desired path. Moreover, there was the inverse correlation between the trapped cluster size and the incident frequency. [Preview Abstract] 

KP1.00038: Propagation and Dissolution of CO$_{2}$ bubbles in Algae Photobioreactors Srinivas Kosaraju Research grade photobioreactors are used to study and cultivate different algal species for biofuel production. In an attempt to study the growth properties of a local algal species in rain water, a custom made bioreactor is designed and being tested. Bioalgae consumes dissolved CO$_{2}$ in water and during its growth cycle, the consumed CO$_{2}$ must be replenished. Conventional methods use supply of air or CO2 bubbles in the growth medium. The propagation and dissolution of the bubbles, however, are strongly dependent on the design parameters of the photobioreactor. In this paper, we discuss the numerical modeling of the air and CO$_{2}$ bubble propagation and dissolution in the photobioreactor. Using the results the bioreactor design will be modified for maximum productivity. [Preview Abstract] 

KP1.00039: Coalescence preference in densely packed bubbles Yeseul Kim, Su Jin Lim, Bopil Gim, Byung Mook Weon Coalescence preference is the tendency that a merged bubble from the contact of two original bubbles (parent) tends to be near to the bigger parent. Here, we show that the coalescence preference can be blocked by densely packing of neighbor bubbles. We use highspeed highresolution Xray microscopy to clearly visualize individual coalescence phenomenon which occurs in micro scale seconds and inside dense packing of microbubbles with a local packing fraction of $\sim$ 40{\%}. Previous theory and experimental evidence predict a power of 5 between the relative coalescence position and the parent size. However, our new observation for coalescence preference in densely packed microbubbles shows a different power of 2. We believe that this result may be important to understand coalescence dynamics in dense packing of soft matter. [Preview Abstract] 

KP1.00040: Experimental technique for observing free oscillation of a spherical gas bubble in highly viscous liquids. Takehiro Nakajima, Keita Ando 

KP1.00041: Abstract Withdrawn Surface enhancement is often is the primary approach for improved heat transfer performance of twophase thermal systems particularly when they operate in nucleate boiling regime. This paper exploits the modeling capability developed by Yazdani et. al. for simulation of nucleate boiling and transition to critical heat flux to study the nucleation phenomenon on various enhanced structures. The multiscale of twophase flow associated with boiling phenomena is addressed through combination of deterministic CFD for the macroscale transport, asymptotic based representation of microlayer, and stochastic representation of surface roughness so as to allow a highfidelity simulation of boiling on an arbitrary surface. In addition, given the excessive complexity of surface structures often used for enhancement of boiling heat transfer, a phasefieldbased method is developed to generate the structures where the numerical parameters in the phasefield model determine the topology of a given structure. The ``generated'' structure is then embedded into the twophase flow model through virtual boundary method for the boiling simulation. The model is validated against experimental data for the boiling curve and the critical heat flux as well as nucleation and bubble dynamics characteristics. 

KP1.00042: COMPRESSIBLE FLOW 

KP1.00043: Turbulent energy flux generated by shock/homogeneousturbulence interaction Krishnendu Sinha, Russell Quadros, Johan Larsson Highspeed turbulent flows with shock waves are characterized by high localized surface heat transfer rates. Computational predictions are often inaccurate due to the limitations in modeling of the unclosed turbulent energy flux in the highly nonequilibrium regions of shock interaction. In this paper, we investigate the turbulent energy flux generated when homogeneous isotropic turbulence passes through a nominally normal shock wave. We use linear interaction analysis where the incoming turbulence is idealized as being composed of a collection of twodimensional planar vorticity waves, and the shock wave is taken to be a discontinuity. The nature of the postshock turbulent energy flux is predicted to be strongly dependent on the incidence angle of the incoming waves. The energy flux correlation is also decomposed into its vortical, entropy and acoustic contributions to understand its rapid nonmonotonic variation behind the shock. Threedimensional statistics, calculated by integrating twodimensional results over a prescribed upstream energy spectrum, are compared with available direct numerical simulation data. A detailed budget of the governing equation is also considered in order to gain insight into the underlying physics. [Preview Abstract] 

KP1.00044: COMPUTATIONAL FLUID DYNAMICS 

KP1.00045: Effect of the Convected Terms in the Transient Viscoelastic Flow Nariman Ashrafi, Meysam Mohamadali The influence of fluid elasticity is examined for the plane Couette flow (PCF) of a Johnson Segalman (J.S) fluid. The model takes into account the interrelations of velocity gradients and stress components through introduction of appropriate coefficients in the elastic terms of constitutive equation. The flow field is obtained from the conservation and constitutive equations using the Galerkin projection method. Both inertia and normal stress effects are included. Effect of several values of governing parameters such as introduced coefficients, Reynolds number and Weissenberg number on velocity and normal and shear stresses profiles are explored in detail. The results show that the oscillating behavior of velocity profile tends to grow as the coefficients increase. The shear stress behavior is dependent on the coefficients of the convected terms and the flow properties. For higher Reynolds the shear stress reaches a maximum and then decreases to minimum. From a numerical point of view, the model also allows for the velocity and stress components to be represented by truncated series. [Preview Abstract] 

KP1.00046: Highperformance and highorder numerical methods for 2D NavierStokes equations Vinicius Henrique Aurichio, Attilio Cucchieri, Maria Luisa Bambozzi de Oliveira Since numerical simulation of a flow is a computationallyintensive problem, our main goal is to develop numerical methods  to solve the fluid equations of motion (compressible NavierStokes) in 2D  that are also suitable for the highperformance computing framework. We study known methods, such as fluxsplitting, MacCormack, and compact schemes, to guide our search. In particular, we consider some highorder versions of these methods, since they allow for highresolution with less grid points, possibly reducing the computation times. Our effort is focused on obtaining shockcapturing, multiscale, lownumerical dissipation methods. [Preview Abstract] 

KP1.00047: Simulation of High Re Boundary Layer Flows on Uniform Grids Using Immersed Boundaries with Vorticity Confinement Subhashini Chitta, John Steinhoff This paper describes the use of Vorticity Confinement (VC) to efficiently treat complex blunt bodies with thin shed vortex sheets and attached boundary layers. Because these flows involve turbulence in the vortical regions, there is currently no \textit{ab initio} method to treat them on current or foreseeable computers. In fact, in spite of years of turbulence modeling efforts (such as LES or RANS), serious flaws in aerodynamic design involving vortex shedding may still be left undetected until the expensive prototype or production stage. Our basic premise is that, for a class of realworld problems requiring simulating ensembles of flow conditions for overall accuracy, conventional turbulence models suffer cost constraints. For these reasons, VC is used to rapidly simulate many operating conditions, as is often done in expensive testing programs for flying prototypes, and in realistic simulations. To achieve dramatically lower computational cost, VC treats the entire flow in a uniform, coarse grid with solid surfaces ``immersed'' in the grid so that they can be quickly generated for many configurations with no requirement for adaptive or conforming fine grids. Also, the VC method has the efficiency of panel methods, but the generality and ease of use of Euler equation methods. [Preview Abstract] 

KP1.00048: Numerical analysis of rough wall effect on liddriven cavity flow using Lattice Boltzmann Method Arman Safdari, S. M. Reza Attarzadeh, Kyung Chun Kim In this paper, the numerical investigation of two dimensional incompressible flow in a liddriven cavity with series of squared roughness on the basal wall is carried out. Understanding the dynamic of fluidparticles interaction is of interest in different industrial applications such as sedimentation process. Two numerical methods are applied for validation purpose: Transient modeling based on Finite Volume Method, and Lattice Boltzmann method based on the discrete Boltzmann equation. The flow field is investigated for range of Reynolds number; 100, 700 and 1000 using a fine grid mesh around the roughened wall. The effect of wallroughness as an influencing parameter on formation of the central vortex inside the cavity is investigated. It is shown that the size of the downstream secondary eddies become smaller with either increasing Reynolds number or increasing the number of roughed features. Dominant effect of secondary eddies were observed by increasing the size of the wall roughness which mimics the influence of sedimented particles inside a cavity. Interesting features of the flow, cavity features and the boundary conditions are discussed in details. [Preview Abstract] 

KP1.00049: Largeeddy simulation of vortex streets and dispersion behind highrise buildings BeomSoon Han, SeungBu Park, JongJin Baik Understanding flow and dispersion in densely builtup urban areas is one of the important problems in the field of urban fluid mechanics. Nowadays, sophisticated numerical models and highresolution urban morphology data enable us to study detailed flow structures in real urban areas. Simulations with highresolution urban morphology data show very complex flow structures in several studies. Here, we examine turbulent flow patterns and associated pollutant dispersion near and, particularly, behind highrise buildings using the parallelized largeeddy simulation model (PALM) and highresolution urban morphology data. The study area selected is a highly builtup area of Seoul, South Korea. It is shown that turbulent wakes are produced behind highrise buildings and vortex streets appear in the places where turbulent wakes occur. The vortex street seems to be related to strong updrafts and ejections that appear downwind of highrise buildings. The vortex street is found to affect pollutant dispersion. Various factors that influence the evolution and structure of vortex streets will be presented and discussed along with involved dispersion mechanisms. [Preview Abstract] 

KP1.00050: A computational framework for the quantification of rare events in systems with instabilities Themistoklis Sapsis, Mustafa Mohamad, Will Cousins We consider the problem of probabilistic quantification of dynamical systems exhibiting heavy tailed distributions. These heavy tail features are associated with rare transient re sponses due to the occurrence of internal instabilities. Systems with these characteristics can be found in a variety of areas including mechanics, fluids, and waves. Here we are interested for the development of a computational approach, a probabilisticdecompositionsynthesis method that will take into account the nature of these internal instabilities and will inexpensively provide the nonGaussian probability density function for the quantities of interest. Our approach relies on the decomposition of the statistics to a stable Gaussian core and a heavytailed distribution. Statistics in the stable region are analytically characterized using a Gaussian approximation approach, while the nonGaussian distributions associated with the intermittently unstable region of the phase space, are inexpen sively quantified through reducedorder methods. Applications are presented for nonlinear water waves as well as subjected mechanical systems. [Preview Abstract] 

KP1.00051: CONVECTION AND BUOYANCY DRIVEN FLOWS 

KP1.00052: Validity of classical scaling laws in laminar channel flow with periodic spacerlike obstacles Wilko Rohlfs, John H. Lienhard Laminar channel flows with periodic obstacles occur in different technical applications involving heat and mass transfer. They are present in membrane technologies such as electrodialysis or spirally wound membrane modules. For process design, classical scaling laws of heat and mass transfer are typically used. The laws scale the transfer (Sherwood) number, $Sh$, to the hydrodynamic Reynolds, $Re$, the fluid specific Schmidt number, $Sc$, and to some dimensionless geometric parameters, $G$, in a classical form like $Sh = C Re^{\alpha} Sc^{\beta} G^{\gamma}$. However, the validity of those classical scaling laws is limited to the region where the concentration boundary layer develops as it is well known that the transfer numbers approach a constant (Reynolds and Schmidt independent) value in the developed region of a laminar channel flow. This study examines numerically the validity of the scaling laws if the channel flow is interrupted periodically by cylindrical obstacles of different size and separation distance. In the developed region, a Schmidt and Reynolds number dependency is found and associated to wallnormal flow induced by the obstacles, for which this dependency varies with obstacle size and separation distance. [Preview Abstract] 

KP1.00053: Numerical Modeling of Surface and Volumetric Cooling using Optimal T and Yshaped Flow Channels Srinivas Kosaraju The T and Yshaped flow channels can be optimized for reduced pressure drop and pumping power. The results of the optimization are in the form of geometric parameters such as length and diameter ratios of the stem and branch sections. While these flow channels are optimized for minimum pressure drop, they can also be used for surface and volumetric cooling applications such as heat exchangers, air conditioning and electronics cooling. In this paper, we studied the heat transfer characteristics of multiple T and Yshaped flow channel configurations using numerical simulations. All configurations are subjected to same pumping power and heat generation constraints and their heat transfer performance is studied. [Preview Abstract] 

KP1.00054: Numerical Modeling and Optimization of Warmwater Heat Sinks Yaser Hadad, Paul Chiarot For cooling in large datacenters and supercomputers, water is increasingly replacing air as the working fluid in heat sinks. Utilizing water provides unique capabilities; for example: higher heat capacity, Prandtl number, and convection heat transfer coefficient. The use of warm, rather than chilled, water has the potential to provide increased energy efficiency. The geometric and operating parameters of the heat sink govern its performance. Numerical modeling is used to examine the influence of geometry and operating conditions on key metrics such as thermal and flow resistance. This model also facilitates studies on cooling of electronic chip hot spots and failure scenarios. We report on the optimal parameters for a warmwater heat sink to achieve maximum cooling performance. [Preview Abstract] 

KP1.00055: Buoyancy and blockage effects on transient laminar opposing mixed convection heat transfer from two horizontal confined isothermal cylinder in tandem Lorenzo Mart\'InezSu\'astegui, Erick Salcedo, Juan Cajas, C\'esar Trevi\~no Transient mixed convection in a laminar crossflow from two isothermal cylinders in tandem arrangement confined inside a vertical channel is studied numerically using the vorticitystream function formulation of the unsteady twodimensional NavierStokes and energy equations. Numerical experiments are performed for a Reynolds number based on cylinder diameter of Re $=$ 200, Prandtl number of Pr $=$ 7, blockage ratio of D/H $=$ 0.2, a pitchtodiameter ratio of L/D $=$ 2, and several values of buoyancy strength or Richardson number Ri $=$ Gr/Re$^{\mathrm{2}}$. The results reported herein demonstrate how the wall confinement, interference effects and opposing buoyancy affect the flow structure and heat transfer characteristics of the cylinder array. [Preview Abstract] 

KP1.00056: DROPS 

KP1.00057: Oil in Water: An Experimental Study of Splashing and Entrainment from Droplets and Jets Raina Mittal, Kristen Halper, Rajat Mittal This study is motivated by the interaction between oil and water that is associated with events such as oil spills, oil slicks and underwater oil leaks. For instance, the impact of rain drops on a floating oil slick can lead to the formation of satellite droplets and oil entrainment into the water, that could subsequently lead to further dispersion of the oil slick. Furthermore, the dynamics of high speed jets of oil in water is relevant to underwater oil leaks, but the motion of such oil jets is not well studied. In the current study, we use highspeed videography with various types of commonly available oils to study the impact of water droplets on oil slicks of varying thicknesses. Results show that an oil slick with intermediate thickness leads to the most significant formation of satellite droplets. This behavior seems to be related to the competing effect of oil viscosity and surface tension on the dynamics of splashing. We also use highspeed videography to study the motion and dispersion of underwater oil jets and correlate the breakup of the jet with the inclination of the jet. [Preview Abstract] 

KP1.00058: Impact of a single drop on the same liquid: formation, growth and disintegration of jets G. Gilou Agbaglah, Robert Deegan One of the simplest splashing scenarios results from the impact of a single drop on on the same liquid. The traditional understanding of this process is that the impact generates a jet that later breaks up into secondary droplets. Recently it was shown that even this simplest of scenarios is more complicated than expected because multiple jets can be generated from a single impact event and there are bifurcations in the multiplicity of jets. First, we study the formation, growth and disintegration of jets following the impact of a drop on a thin film of the same liquid using a combination of numerical simulations and linear stability theory. We obtain scaling relations from our simulations and use these as inputs to our stability analysis. We also use experiments and numerical simulations of a single drop impacting on a deep pool to examine the bifurcation from a single jet into two jets. Using high speed Xray imaging methods we show that vortex separation within the drop leads to the formation of a second jet long after the formation of the ejecta sheet. [Preview Abstract] 

KP1.00059: Aqueous Polymer in water alter the Coffeering effect Changdeok Seo, Daeho Jang, Wonhwi Na, Sera Park, Sehyun Shin When evaporating in droplet system, small particles move toward an edge by outward capillary flow. This phenomenon is known as coffeering effect. In experiments that are required to uniformly accumulate particles, this effect can be fatal. In spite of recent challenges for suppressing the coffeering effect, it is still insufficiently controlled in film and droplet with various solutions. For deliberate applications, various materials should be out of influence of coffeering effect. In this research, we used a biocompatible and aqueous polymer, polyethylene glycol (PEG) for altering the coffeering effect. The influence of PEG on the evaporation of drying colloidal droplets is examined in a wide range of initial concentrations. Adding PEG to water causes a strong vortex flow near the edge of droplet and subsequently leads to significantly uniform patterns of colloidal particle deposition after evaporation. We found the vortex phenomenon by combination of radially outward capillary flow and radially inward Marangoni flows are induced by the radial variation of polymer concentration along the air?water interface. Furthermore, increasing polymer concentration significantly alters the characteristic of “Marangoni Vortex” and leads to reproducible patterning of conical structures. [Preview Abstract] 
(Author Not Attending)

KP1.00060: Superhydrophobiclike tunable droplet bouncing on slippery liquid interfaces Chonglei Hao, Zuankai Wang Droplet impacting on solid or liquid interfaces is a ubiquitous phenomenon in nature. Although complete rebound of droplets is widely observed on superhydrophobic surfaces, the bouncing of droplets on liquid is usually vulnerable due to easy collapse of entrapped air pocket underneath the impinging droplet. Here, we report a superhydrophobiclike bouncing regime on thin liquid film, characterized by the contact time, the spreading dynamics, and the restitution coefficient independent of underlying liquid film. Through experimental exploration and theoretical analysis, we demonstrate that the manifestation of such a superhydrophobiclike bouncing necessitates an intricate interplay between the Weber number, the thickness and viscosity of liquid film. Such insights allow us to tune the droplet behaviors in a wellcontrolled fashion. We anticipate that the combination of superhydrophobiclike bouncing with inherent advantages of emerging slippery liquid interfaces will find a wide range of applications. [Preview Abstract] 

KP1.00061: Effect of surface morphology on antiicing DuckGyu Lee, ThanhBinh Nguyen, WanDoo Kim, Hyuneui Lim A water drop on a subcooled surface undergoes solidification, and it is well known that the antiicing effects such as delayed freezing time and low adhesion force are determined by surface morphology. To quantitatively understand the effect of surface morphology on antiicing behavior, we first theoretically predict the freezing time of a water drop on a subcooled micro patterned substrate and show that the time delay is in good agreement with experimental results. Then we develop a simple theory for the work of adhesion upon consideration the substrate geometrical condition in order to prevent it from being broken due to the adhesion. Finally, we provide the morphological conditions for the pattern under which the freezing time delay is maximized and the work of adhesion is minimized. [Preview Abstract] 

KP1.00062: Spreading of Electrolyte Drops on Charged Surfaces: Electric Double Layer Effects on Drop Dynamics Kyeong Bae, Shayandev Sinha, Guang Chen, Siddhartha Das Drop spreading is one of the most fundamental topics of wetting. Here we study the spreading of electrolyte drops on charged surfaces. The electrolyte solution in contact with the charged solid triggers the formation of an electric double layer (EDL). We develop a theory to analyze how the EDL affects the drop spreading. The drop dynamics is studied by probing the EDL effects on the temporal evolution of the contact angle and the base radius ($r$). The EDL effects are found to hasten the spreading behaviour  this is commensurate to the EDL effects causing a ``philic'' tendency in the drops (i.e., drops attaining a contact angle smaller than its equilibrium value), as revealed by some of our recent papers. We also develop scaling laws to illustrate the manner in which the EDL effects make the $r$ \textit{versus} time ($t$) variation deviate from the well known $r\sim t^{n}$ variation, thereby pinpointing the attainment of different EDLmediated spreading regimes. [Preview Abstract] 

KP1.00063: ELECTROKINETIC FLOWS 

KP1.00064: Quantization method for describing the motion of celestial systems Victor Christianto, Florentin Smarandache Criticism arises concerning the use of quantization method for describing the motion of celestial systems, arguing that the method is oversimplifying the problem, and cannot explain other phenomena, for instance planetary migration. Using quantization method like NottaleSchumacher did, one can expect to predict new exoplanets with remarkable result. The ``conventional'' theories explaining planetary migration normally use fluid theory involving diffusion process. Gibson have shown that these migration phenomena could be described via NavierStokes approach. Kiehn's argument was based on exactmapping between Schrodinger equation and NavierStokes equations, while our method may be interpreted as an oversimplification of the real planetary migration process which took place sometime in the past, providing useful tool for prediction (e.g. other planetoids, which are likely to be observed in the near future, around 113.8AU and 137.7 AU). Therefore, quantization method could be seen as merely a ``plausible'' theory. We would like to emphasize that the quantization method does not have to be the true description of reality with regards to celestial phenomena. This method could explain some phenomena, while perhaps lacks explanation for other phenomena. [Preview Abstract] 

KP1.00065: Electric field control of a fluid transfer between freely suspended and sessile droplets Suhwan Choi, Alexei Saveliev This works explore direct fluid transfer between microdroplets using liquid bridges stabilized by ac electric field. Experiments are performed with freely and sessile microdroplets of pure glycerol and water with dye. The droplets are placed along electric field directions in a cell with parallel plate electrodes filled with silicone oil. The electrical conductivity of droplets is changed from 1 to 200 $\mu$S/cm by adding dye solutions. Liquid bridges interconnecting two microdroplets can be created using an alternating electric field from 0.3 to 0.7 kV/mm with a frequency of 10.3 kHz. For such bridging fluid can be transferred through the liquid bridge from one droplet to another due to the pressure difference. The process is recorded using a CCD camera. The fluid flowrates in the range from $\sim$ 100 to 10 nL/s are recorded with different electric fields and liquid conductivity. We propose that the manipulation of the liquid bridge will be the method in which small fluid volumes are dispensed. [Preview Abstract] 

KP1.00066: The capacitance of ionic liquid electric double layer near nanostructured electrodes Yun Sung Park, Myung Mo Ahn, In Seok Kang The electric double layer capacitors (EDLC) with nanostructured electrodes have attracted much attention of researchers due to their high power density and long life time. Recently, the ionic liquids are used as an electrolyte of EDLC owing to their electrochemical stability. When ionic liquids are used as an electrolyte, the interrelations between the electric double layer of ionic liquids and the nanostructured electrode must be studied. In this study, the EDLC systems with nanostructured electrodes and ionic liquids are simulated by solving the modified PoissonBoltzmann equation proposed by Bazant, Storey, and Kornyshev (Phys. Rev. Lett. \textbf{106}, 046102 (2011)) with COMSOL Multiphysics. Several electrode geometries including exohedral, endohedral and arrayed shapes with different length scales are simulated. The potential and charge distributions in the normal direction to the electrode surface are analyzed. The capacitance per unit area is obtained and compared to that of flat electrode. The structure determines the space for counterion packing and coion gathering, thus has crucial effects on electric double layer capacitance. The critical increase of capacitance with nanoscale confined space is observed with low electrode potential. [Preview Abstract] 

KP1.00067: Electroosmotic Flow in Rigid and Soft Nanochannels: Effects of Solvent Polarization Lucas Myers, Shayandev Sinha, Siddhartha Das Electroosmotic (EOS) flow, triggered by the interaction of an applied electric field and the charge density gradient generated at the interface of a solidliquid interface, has evolved as an extremely popular technique of driving liquid in micronanochannels. Unlike the PoissonBoltzmann (PB) approach based analysis of the EOS transport, there is relatively little work on studying EOS flows in a framework beyond the PB approach. Here we provide a theory for the EOS transport using a LangevinBikerman (LB) model that simultaneously accounts for two important nonPB elements, namely solvent polarization and finite ion sizes. Our analysis reveals new nondimensional parameters that influence the EOS flow. More importantly, we identify an effective electric double layer (EDL) thickness that dictates the flow characteristics. The central finding of our calculations is that for the realistic set of parameters, nonPB influences always enhances the electroosmotic flow. In the next part of the study, we highlight the nontrivialities associated with the case where the nanochannels become ``soft,'' i.e., the nanochannel walls are grafted with polyelectrolyte layers that affect both the electrostatic potential distribution as well as the drag force associated with the electroosmotic flow. [Preview Abstract] 

KP1.00068: Instantaneous velocity measurement of AC electroosmotic flows by laser induced fluorescence photobleaching anemometer with high temporal resolution Wei Zhao, Fang Yang, Rui Qiao, Guiren Wang Understanding the instantaneous response of flows to applied AC electric fields may help understand some unsolved issues in inducedcharge electrokinetics and enhance performance of microfluidic devices. Since currently available velocimeters have difficulty in measuring velocity fluctuations with frequency higher than 1 kHz, most experimental studies so far focus only on the average velocity measurement in AC electrokinetic flows. Here, we present measurements of AC electroosmotic flow (ACEOF) response time in microchannels by a novel velocimeter with submicrometer spatial resolution and microsecond temporal resolution, i.e. laserinduced fluorescence photobleaching anemometer (LIFPA). Several parameters affecting the ACEOF response time to the applied electric signal were investigated, i.e. channel length, transverse position and solution conductivity. The experimental results show that the EOF response time under a pulsed electric field decreases with the reduction of the microchannel length, distance between the detection position to the wall and the conductivity of the solution. This work could provide a new powerful tool to measure AC electrokinetics and enhance our understanding of AC electrokinetic flows. [Preview Abstract] 

KP1.00069: Investigation of liquid properties in extended nanospaces using streaming potential/current system Kyojiro Morikawa, Yutaka Kazoe, ChiChang Chang, Takehiko Tsukahara, Kazuma Mawatari, Takehiko Kitamori Understanding liquid properties in extended nanospace (101000 nm) is important for the evolution of nanofluidic devices. Liquid properties are expected to be changed by the nanoconfinement, because the extended nanospace represents a transitional regime from single molecules to the bulk condensed phase. In this study, we developed nonprobe measurement system of dielectric constant and electric conductivity of water in the extended nanospaces using streaming potential/current system. The results showed that dielectric constant in extended nanospaces was approximately 3 times lower than that in bulk, and that conductivity in extended nanospace was approximately 500 times higher than that in bulk. The measured conductivity was consistent with the calculated one, which was determined using dielectric constants measured in extended nanospaces and electric double layer (EDL) model. It will be important information for nanofluidics. [Preview Abstract] 

KP1.00070: ENERGY 

KP1.00071: The Hybrid Sterling Engine: boosting photovoltaic efficiency and deriving mechanical work from fluid expansion and heat capture Nathan Beets Two major problems with many third generation photovoltaics is their complex structure and greater expense for increased efficiency. Spectral splitting devices have been used by many with varying degrees of success to collect more and more of the spectrum, but simple, efficient, and costeffective setups that employ spectral splitting remain elusive. This study explores this problem, presenting a solar engine that employs stokes shifting via laser dyes to convert incident light to the wavelength bandgap of the solar cell and collects the resultant infrared radiation unused by the photovoltaic cell as heat in ethylene glycol or glycerin. When used in conjunction with micro turbines, fluid expansion creates mechanical work, and the temperature difference between the cell and the environment is made available for use. The effect of focusing is also observed as a means to boost efficiency via concentration. Experimental results from spectral scans, vibrational voltage analysis of the PV itself and temperature measurements from a thermocouple are all compared to theoretical results using a program in Mathematica written to model refraction and lensing in the devices used, a quantum efficiency test of the cells, the absorption and emission curves of the dues used to determine the spectrum shift, and the various equations for fill factor, efficiency, and current in different setups. An efficiency increase well over 50{\%} from the control devices is observed, and a new solar engine proposed. [Preview Abstract] 

KP1.00072: EXPERIMENTAL TECHNIQUES 

KP1.00073: A rapid filtering and reconstruction method of twodimensional image velocimetry signals using a noniterative PODmethod Jonathan Higham, Wernher Brevis, Christopher Keylock A method is presented, based on Proper Orthogonal Decomposition (POD), for the detection and estimation of outliers in twodimensional signals. In experimental fluid mechanics, for a number of reasons, two dimensional data obtained using techniques such as Particle Image Velocimetry often contain outliers. The proposed methodology is based on the assumption that statistically significant outliers can be identified as abnormalities in the evolution of the temporal POD coefficients and as changes to the eigenvalues. Unlike previous methods, the estimation technique in the current method is noniterative. It is instead dependent on a correction of a parameter introduced to search for abnormal, outlier induced magnitudes in the modal decomposition. The method is benchmarked by synthetically simulating outliers applied to two data sets: One data set is obtained experimentally using Particle Image Velocimetry; the other is based on a numerical simulation. The results demonstrate that the proposed approach is able to identify the outliers reliably and correct them with acceptable accuracy. [Preview Abstract] 

KP1.00074: Development of threedimensional optical correction method for reconstruction of flow field in droplet Han Seo Ko, Yeonghyeon Gim, SeungHwan Kang A threedimensional optical correction method was developed to reconstruct dropletbased flow fields. For a numerical simulation, synthetic phantoms were reconstructed by a simultaneous multiplicative algebraic reconstruction technique using three projection images which were positioned at an offset angle of 45°. If the synthetic phantom in a conical object with refraction index which differs from atmosphere, the image can be distorted because a light is refracted on the surface of the conical object. Thus, the direction of the projection ray was replaced by the refracted ray which occurred on the surface of the conical object. In order to prove the method considering the distorted effect, reconstruction results of the developed method were compared with the original phantom. As a result, the reconstruction result of the method showed smaller error than that without the method. The method was applied for a Taylor cone which was caused by high voltage between a droplet and a substrate to reconstruct the threedimensional flow fields for analysis of the characteristics of the droplet. [Preview Abstract] 

KP1.00075: Experimental Analysis of Flow over a Highly Maneuverable Airframe Jonathan Spirnak, Michael Benson, Bret Van Poppel, Christopher Elkins, John Eaton One way to reduce the collateral damage in war is by increasing the accuracy of indirect fire weapons. The Army Research Laboratory is currently developing a Highly Maneuverable Airframe (HMA) consisting of four deflecting canards to provide inflight maneuverability while fins maintain short duration aerodynamic stability. An experiment was conducted using Magnetic Resonance Velocimetry (MRV) techniques to gather three dimensional, threecomponent velocity data for fluid flow over a scaled down HMA model. Tests were performed at an angle of attack of 2.3$^{\circ}$ and canard deflection angles of 0$^{\circ}$ and 2$^{\circ}$. The resulting data serve to both validate computational fluid dynamics (CFD) simulations and understand the flow over this complex geometry. Particular interest is given to the development of the tip and inboard vortices that originate at the canard/body junction and the canard tips to determine their effects on airframe stability. Results show the development of a strong tip vortex and four weaker inboard vortices off each canard. Although the weaker inboard vortices dissipate rapidly downstream of the canard trailing edges, the stronger tip vortices persist until reaching the fins approximately six chord lengths downstream of the canard trailing edges. [Preview Abstract] 

KP1.00076: Photochromic flow visualization in silicone oil for demonstrations and experiments Enrico Fonda, Stephen R. Johnston, Devesh Ranjan, Katepalli R. Sreenivasan Photochromic dyes change color when illuminated, usually with UV light. As tracers for flow visualization they are nonintrusive, can selectively color the fluid, and are suitable for complex and confided flows. Availability of cheap 405nm highpower lasers combined with advances in image acquisition and imageprocessing technology, make these tracers particularly effective in creating convenient and engaging educational demonstrations as well as in qualitatively exploring flow structures. We present two lowcost demonstrations: laminarflow reversibility using a TaylorCouette device and a thermal convection flow. We also report our experience in studying large scales in high Prandtl numbers RayleighB\'enard convection. [Preview Abstract] 

KP1.00077: Effects of Adding Nanoparticles on Boiling and Condensing Heat Transfer inside a horizontal round tube Mohsen Sheikholeslami, Mohammadkazem Sadoughi, Hamed Shariatmadar, Mohammad Ali AkhavanBehabadi An experimental investigation is performed on heat transfer evaluation of a nanorefrigerant flow during condensation and evaporation inside a horizontal round tube. Experiments are carried out for three working fluid types including: i) pure refrigerant (R600a); ii) refrigerant/lubricant (R600a/oil); and iii) nanorefrigerant: refrigerant/lubricant/nanoparticles (R600a/oil/CuO). Nanoparticles are added to the lubricant and their mixture is mixed with pure refrigerant. Therefore, nanorefrigerants (R600a/oil/CuO) are prepared by dispersing CuO nanoparticles with different fractions of 0.5{\%}, 1{\%} and 1.5{\%} in the baseline mixture (R600a/oil). Effects of different factors including vapor quality, mass flux, and nanoparticles on the heat transfer coefficient are examined for both of condensation and evaporation flows, separately. The results shows that maximum heat transfer augmentation of 79{\%} and 83{\%} are achieved by using the refrigerant/lubricant/nanoparticles mixture, in comparison with the pure refrigerant case in condensation and evaporation, respectively which are occurred for nanorefrigerant with 1.5{\%} mass fraction in both of them. [Preview Abstract] 

KP1.00078: Shear velocity and wall position determination from particle image velocimetry data with seed centroid correction Jeff Harris, Blake Lance, Richard Skifton, Barton Smith Two methods of computing the wall shear velocity from highresolution particle image velocimetry (PIV) measurements are compared with and without a correction that accounts for seed gradient near the wall. It is crucial to know the wall position when computing the wall shear stress, but this can be difficult due to laser scatter on a wall. Furthermore, PIV is well known to be biased near walls due to seeding gradients. We compensate for these effects by replacing the crossstream location of each vector with a value based on the centroid of the seeding in each interrogation region. The shear velocity and wall position resulting from methods outlined in the literature are presented. The boundary layer cases presented are influenced by buoyancy and the efficacy of these methods for convective flow will be discussed. [Preview Abstract] 
(Author Not Attending)

KP1.00079: Inductively Coupled Discharge and PostDischarge with RF of Ne Neslihan Sahin, Murat Tanisli, Sercan Mertadam Plasma, which is the fourth state of matter, can be produced in laboratories in different ways. In this study, the inductively radio frequency (RF) plasma at low pressure in the quartz glass reactor prepared for special conditions is obtained. This generated plasma is nonlocal thermodynamics plasma and it includes different particles such as positive ions, electrons and neutral particles. Inductively coupled neon's discharge and postdischarge characteristic properties are examined with optical emission spectroscopy (OES) and then OES is used for determining electron temperature. Differences between discharge and postdischarge zone under the same conditions are obtained. It is investigated how gas filling pressure, the applied RF power to gases and gas flowing rate affect neon inductively coupled RF discharge and postdischarge. [Preview Abstract] 

KP1.00080: FREESURFACE FLOWS 

KP1.00081: Generating a soliton splash through variational modelling and experiments Anna Kalogirou, Onno Bokhove Mathematical modelling of water waves in tanks with wave generators is demonstrated by investigating variational methods asymptotically and numerically. A reduced potential flow water wave model is derived using variational techniques, which is based on the assumptions of waves with small amplitude and large wavelength. This model consists of a set of modified BenneyLuke equations describing the deviation from the still water surface $\eta(x,y,t)$ and the bottom potential $\Phi(x,y,t)$, and includes a timedependent gravitional potential mimicking a removable ``sluice gate''. The asymptotic model is solved numerically using the automated system Firedrake. In particular, a (dis)continuous Galerkin finite element method is used, together with symplectic integrators for the time discretisation. As a validation, the numerical results are compared to a soliton splash experiment in a long water channel with a contraction at its end, resulting after a sluice gate is removed at a finite time. [Preview Abstract] 

KP1.00082: FLOW CONTROL 

KP1.00083: Effect of synthetic roughness on a turbulent channel flow Javier Combariza, Jesus RamirezPastran, Carlos DuqueDaza A turbulent channel flow featuring single step synthetic roughness at the bottom wall was examined using numerical experiments. An incompressible flow solver using LES as turbulence model was employed to study some turbulence variables as well as Qcriterion coherent structures. Roughness was attained by inserting a small step, stretching along the channel spanwise direction in the bottom wall. Three different values for the step width were used. Correlations between the steps width and skinfriction coefficients are calculated. Coherent structures using the QCriterion are constructed using different threshold values. By examining the evolution of the Qstructures, the effect of the perturbation is characterized in the nearwall region. Consistency between skinfriction coefficients and Qstructures evolution trends is observed in each case. Comparison between some of the TKE terms in the modified channel flow and those in a smooth channel flow, allow to identify the effect of the the synthetic roughness on the turbulent behaviour. Finally, a simple description of the overall effect of the presence of the perturbation on the turbulent flow is brought about by associating the Qstructures with the strong recirculation zones formed in the nearwall region close to the steps. [Preview Abstract] 

KP1.00084: Sweeping and redevelopment of longitudinal vortices in a turbulent boundary layer by injecting bubble swarms Hyun Jin Park, Yuji Tasaka, Yuichi Murai We performed injection of bubble swarms, which consist of leading air films and following smaller bubbles, into a turbulent channel flow to investigate interaction between turbulent vortices and small air films. Advection of the air films flowing along the channel wall is faster than the streamwise vortices in a turbulent boundary layer, and thus the vortices in the boundary layer are swept by the air films. Our question is what happening on the vortices after sweeping? We visualized the vortices, and it elucidated that the swept vortices survive beneath the air films without dissipating and bursting. This was also confirmed on the corresponding measurement of Reynolds shear stress. Then the vortices return to the wall after escaping from beneath the air films. After that the redevelopment of the vortices occurs and original condition of the boundary layer is restored. Reduction of Reynolds shear stress is still continued even beneath smaller bubbles in middle part of the bubble swarms and it suggests that redevelopment of Reynolds shear stress event, bursting of streamwise vortices mainly, cannot occur quickly even with survival of the vortices. As a result, the bubble swarms reduce frictional drag more than continuously injected bubbles at the same volume fraction of bubbles. [Preview Abstract] 

KP1.00085: Reduction of aerodynamic friction drag of moving bodies using a MicrowaveDielectricBarrierDischarge actuator controlling the boundary layer Thiery Pierre A new plasma device named MDBD (Microwave Dielectric Barrier Discharge) is used for controlling the boundary layer in order to reduce the drag force. A compact resonant UHF structure comprising a resonant element in the form of a quarterwave antenna creates a miniplasma insulated from the UHF electrodes by mica sheets. Additional electrodes induce an electric field in the plasma and transiently move the ions of the plasma. The high collision rate with the neutral molecules induce the global transient flow of the neutral gas. The temporal variation of the applied electric field is chosen in order to obtain a modification of the local boundary layer. First tests using an array of MDBD plasma actuators are underway (see Patent ref. WO 2014111469 A1). [Preview Abstract] 

KP1.00086: FLOW INSTABILITY 

KP1.00087: Transition in Hypersonic Boundary Layers: Role of Dilatational Waves Yiding Zhu, Chuanhong Zhang, Qing Tang, Huijing Yuan, Jiezhi Wu, Shiyi Chen, Cunbiao Lee, Mohamed Gadelhak Transition and turbulence production in a hypersonic boundary layer is investigated in a Mach 6 quiet wind tunnel using Rayleighscattering visualization, fastresponse pressure measurements, and particle image velocimetry. It is found that the secondmode instability is a key modulator of the transition process. Although the second mode is primarily an acoustic wave, it causes the formation of highfrequency vortical waves. While the growing acoustic wave itself is rapidly annihilated due to its large and sharp dissipation peak that is enhanced by the bulk viscosity, the acoustically generated highfrequency vortical wave keeps growing and triggers a fast transition to turbulence. [Preview Abstract] 

KP1.00088: Effect of surfactant on kinetics of thinning of capillary bridges Emilia Nowak, Nina Kovalchuk, Mark Simmons Kinetics of thinning of capillary bridges is of great scientific and industrial interest being of vital importance for example in various emulsification and microfluidic processes. It is well known that the rate of bridge thinning is proportional to the interfacial tension. Therefore it is expected that the process should slow down by addition of surfactant. The kinetics of capillary bridges in the presence of surfactant was studied by the dripping of liquid from a capillary tip under conditions of nearly zero flow rate (We $\ll$ 1). The tested liquids were aqueous solutions of sodium lauryl ether sulphate (SLES), which is broadly used in personal care products. The viscosity, surfactant activity and adsorption kinetics have been controlled by addition of glycerol and sodium chloride. The study has shown that the kinetics of capillary bridges are determined by dynamic surface tension rather than by its equilibrium value. In particular, the kinetics of the bridge thinning for the 0.1 g L1 aqueous SLES solution is practically the same as that of pure water despite twice lower equilibrium surface tension. [Preview Abstract] 

KP1.00089: Schlieren Imaging of Gravitational Instabilities during Miscible Viscous Fingering of GlycerolWater Systems Daniela Marin, Simone Stewart, Patrick Bunton, Eckart Meiburg, Anne De Wit Viscous fingering occurs when a lower viscosity fluid displaces a higher viscosity fluid causing interfacial instabilities creating fingerlike patterns. In a typical flow, the less viscous fluid is injected into the higher viscous fluid that is between the plates of a HeleShaw cell. In most cases for transparent flows, dye is dissolved into the displacing fluid in order to observe it. This work uses Schlieren imaging of miscible fluid displacements in a horizontal HeleShaw Cell, which reveals new information about the threedimensional nature of VF. A Schlieren system is composed of a parallel light beam, a lens that brings the light to a focus, a cutoff of some type, and a camera. Schlieren does not require dye, ensuring the natural flow of the fluids is undisturbed. Here the imaging system is described followed by results of miscible flows of water in to aqueous glycerol solutions. Structures attributable to threedimensional buoyancydriven flows are readily observed. These results are interpreted in light of recent threedimensional calculations. [Preview Abstract] 

KP1.00090: Spontaneous Formation of Nanopatterns in VelocityDependent DipCoated Organic Films: From Dragonflies to Stripes P. Huber, M. Bai, V. del Campo, P. Homm, P. Ferrari, A. Diama, C. Wagner, H. Taub, K. Knorr, M. Deutsch, M. Retamal, U. Volkmann, T. Corrales We present the structure of thin, nalkane films on the oxide layer of a silicon surface, prepared by dipcoating in a nC$_{\rm 32}$H$_{\rm 66}$/nheptane solution. Electron micrographs reveal two adsorption morphologies depending on the substrate withdrawal speed v. For small v, dragonflyshaped molecular islands are observed. For a large v, stripes parallel to the withdrawal direction are observed. These have a few hundred micrometer lengths and a fewmicrometer lateral separation. With increasing v, the surface coverage first decreases, then increases for $v > v_{cr} \sim 0.15$~mm/s. The critical $v_{cr}$ marks a transition between the evaporation regime and the entrainment regime. The stripes' strong crystalline texture and the well defined separation are due to an anisotropic 2D crystallization in narrow liquid fingers, which presumably results from a Marangoniflowdriven hydrodynamic instability in the evaporating dipcoated films. [Preview Abstract] 

KP1.00091: Effects of inclination and vorticity on interfacial flow dynamics in horizontal and inclined pipes Areti Kiara, Kelli Hendrickson, Yuming Liu The transport of oil and gas in long horizontal pipelines can be significantly affected by the development of violent roll waves and slugs, but the mechanics causing such transitions have not been well understood. To enable the improvement of the prediction of flow transition criteria in long pipelines we perform theoretical analysis and direct numerical simulations of multiphase pipe flows to quantify the roles of inclination and vorticity in the flow dynamics. We find that backflow or flooding may occur even in the absence of disturbances due to inclination effects and obtain criteria on the maximum pipe length for steady flows. We identify and compare the effects of inclination and vorticity on the stability of interfacial wave disturbances. We discuss the mechanisms of nonlinear energy transfer between stable and unstable wave disturbances and present results from direct numerical simulations for the predictions of spectrum evolutions for broadbanded interfacial disturbances in inclined pipes. [Preview Abstract] 

KP1.00092: RayleighTaylor mixing in supernova experiments Nora Swisher, Carolyn Kuranz, David Arnett, Omar Hurricane, Bruce Remington, Harry Robey, Snezhana Abarzhi We report a scrupulous analysis of data in supernova experiments that are conducted at high power laser facilities in order to study corecollapse supernova SN1987A. Parameters of the experimental system are properly scaled to investigate the interaction of a blastwave with heliumhydrogen interface, and the induced RayleighTaylor (RT) mixing of the denser and lighter fluids with timedependent acceleration. We analyze all available experimental images of RT flow in supernova experiments, and measure delicate features of the interfacial dynamics. A new scaling is identified for calibration of experimental data to enable their accurate analysis and comparisons. By proper accounting for the imprint of the experimental conditions, the data set size and statistics are substantially increased. New theoretical solutions are identified to describe asymptotic dynamics of RT flow with timedependent acceleration by applying theoretical analysis. Good qualitative and quantitative agreement is achieved of the experimental data with the theory and simulations. Our study indicates that in supernova experiments, the RT flow is in the mixing regime, the interface amplitude contributes substantially to the characteristic length scale for energy dissipation; the mixing flow may keep order. [Preview Abstract] 

KP1.00093: Qualitative and quantitative features of RayleighTaylor mixing dynamics Aklant Bhowmick, Snezhana Abarzhi, Praveen Ramaprabhu, Varad Karkhanis, Andrew Lawrie We consider dynamics of RayleighTaylor (RT) flow in a large aspect ratio threedimensional domain with square symmetry in the plane for fluids with contrasting densities. In order to quantify the interface evolution from a small amplitude singlemode initial perturbation to advanced stage of RT mixing, we apply numerical simulations using the MOBILE code, theoretical analyses, including group theory and momentum model, as well as parameters describing the interplay between acceleration and turbulence. We find: In RT flow, the fluid motion is intense near the interface and is negligible far from the interface. At late times the growth rates of RT bubbles and spikes may increase without a corresponding increase of lengthscales in the direction normal to acceleration. The parameters describing the interplay between acceleration and turbulence in RT mixing are shown to scale well with the flow Reynolds number and Froude number. [Preview Abstract] 

KP1.00094: Exploring Model Assumptions Through Three Dimensional Mixing Simulations Using a Highorder Hydro Option in the Ares Code Justin White, Britton Olson, Brandon Morgan, Jacob McFarland This work presents results from a large eddy simulation of a high Reynolds number RayleighTaylor instability and RichtmyerMeshkov instability. A tenthorder compact differencing scheme on a fixed Eulerian mesh is utilized within the Ares code developed at Lawrence Livermore National Laboratory. (LLNL) We explore the selfsimilar limit of the mixing layer growth in order to evaluate the kLa Reynolds Averaged Navier Stokes (RANS) model (Morgan and Wickett, Phys. Rev. E, 2015). Furthermore, profiles of turbulent kinetic energy, turbulent length scale, mass flux velocity, and densityspecificvolume correlation are extracted in order to aid the creation a high fidelity LES data set for RANS modeling. [Preview Abstract] 

KP1.00095: Effect of Inhomogeneous Flow on Rayleigh Taylor Instability Sudip Sen The effect of inhomogeneous flow on the stability of RayleighTaylor (RT) mode is investigated in the presence of realistic flow profile which includes both flow shear (first order radial derivative) and flow curvature (second order radial derivative). It is found that contrary to the usual believe the flow curvature has robust effect on the stability of the RT mode  depending on the sign the flow curvature could be stabilizing or destabilizing. The consequence of this novel finding in various interdisciplinary areas will be discussed. [Preview Abstract] 

KP1.00096: High and lowsymmetric coherent structures and dimensional crossover in RichtmyerMeshkov flows Aklant Bhowmick, Snezhana Abarzhi We study the threetotwo dimensional crossover for the nonlinear structures appearing in the nonlinear regime of Richtmeyer Meshkov instability (RMI). This largescale coherent structure is an array of bubbles and spikes that is periodic in the plane normal to the direction of an initial shock (impulsive acceleration) [1]. The flow is assumed to be anisotropic in the plane with the symmetry group p2mm. For the bubbles, there is a twoparameter family of regular asymptotic solutions. Stability of these solutions is studied. The transitions to the flows with the group p4mm and pm as well as properties of the dimensional crossover are analyzed. We find that 3D bubbles in RMI tend to conserve a nearsymmetricshape, and cannot be transformed into 2D bubbles continuously. We discuss the mechanism of secondary instabilities in anisotropic RM flows and the discontinuity of the dimensional crossover, as well as their dependence of the density ratio. [Preview Abstract] 

KP1.00097: On reliable quantification of RichtmyerMeshkov flows Nora Swisher, Milos Stanic, Robert Stellingwerf, Jason Oakley, Riccardo Bonazza, Snezhana Abarzhi We report an integrated study including experiments, Smooth Particle Hydrodynamics simulations, and theoretical and data analyses to reliably quantify RichtmyerMeshkov (RM) flows induced by moderate shocks. The RM evolution is analyzed for realistic gases with different densities (Atwood numbers 0.68, 0.95) driven by moderate shocks (Mach 2.86, 1.95) in case of relatively small amplitude of the initial perturbation (0.06, 0.08 of the perturbation wavelength). Our study includes the systematic consideration of the effects of gamma, the initial perturbation amplitude, and the interference of the perturbation waves. We analyze quantitative and qualitative features of RM dynamics, including the vector and scalar flow fields, the bulk and interface velocities, the largescale interfacial structures and smallscale nonuniformities (reverse jets, hot spots) in the bulk. We argue that a systematic interpretation of RM dynamics from the data and a reliably quantification the RM evolution requires a synergy of the experiments, simulation, and theory. [Preview Abstract] 

KP1.00098: GEOPHYSICAL FLUID DYNAMICS 

KP1.00099: Abstract Withdrawn The shaping of landscapes results from water or wind erosional processes. Here we focus on dissolution processes. We perform laboratory experiments on hard caramel bodies, which dissolve on a short timescale, compared to geological material such as limestone. We highlight the spontaneous appearance of a dissolution pattern with no external flow. When a tilted hard caramel block dissolves, the syrup (denser than water) sinks in the bath and induces a flow, which results in a pattern on the bottom of the block. First parallel stripes appear, which evolve to transversal scallops in about one hour. The whole pattern moves upstream at a slow velocity. The stripes appearance is due to a buoyancydriven instability. By varying the density and the viscosity of the bath, we show that the initial wavelengths of the pattern are in agreement with those given by the solutal RayleighBenard number. Later pattern evolution to scallops results from complex interactions between the flow and the topography. Finally we emphasize that similar mechanism of patterns formation can occur in the dissolution of minerals like salt, but also in the shaping of the bottom face of melting icebergs in the cold seas. 

KP1.00100: ABSTRACT WTIHDRAWN 

KP1.00101: Wind Characteristics of Coastal and Inland Surface Flows Chelakara Subramanian, Steven Lazarus, Tetsuya Jin Lidar measurements of the winds in the surface layer (up to 80 m) inland and near the beach are studied to better characterize the velocity profile and the effect of roughness. Mean and rootmeansquared profiles of horizontal and vertical wind components are analyzed. The effects of variable time (18, 60 and 600 seconds) averaging on the above profiles are discussed. The validity of common surface layer wind profile models to estimate skin friction drag is assessed in light of these measurements. Other turbulence statistics such as auto and cross correlations in spatial and temporal domains are also presented. [Preview Abstract] 

KP1.00102: Direct Statistical Simulation: Ensemble Averaging and Basis Reduction Altan Allawala, Brad Marston Loworder statistics of models of geophysical fluids may be directly accessed by solving the equations of motion for the equaltime cumulants themselves. We investigate a variant of the secondorder cumulant expansion (CE2) in which zonal averaging is replaced by ensemble averaging. Proper orthogonal decomposition (POD) of the second cumulant is used to reduce the dimensionality of the problem. The approach is tested on a quasigeostrophic 2layer baroclinic model of planetary atmospheres by comparison to the traditional approach of accumulating statistics via numerical simulation, and to zonal averaged CE2. [Preview Abstract] 

KP1.00103: Large Eddy Simulations of Kelvin Helmholtz instabilities at high Reynolds number stratified flows Dana Brown, Lou Goodman, Mehdi Raessi Simulations of Kelvin Helmholtz Instabilities (KHI) at high Reynolds numbers are performed using the Large Eddy Simulation technique. Reynolds numbers up to 100,000 are achieved using our model. The resulting data set is used to examine the effect of Reynolds number on various statistics, including dissipation flux coefficient, turbulent kinetic energy budget, and Thorpe length scale. It is shown that KHI are qualitatively different at high Re, up to and including the onset of vortex pairing and billow collapse and quantitatively different afterward. The effect of Richardson number is also examined. The results are discussed as they apply to ocean experiments. [Preview Abstract] 

KP1.00104: Control of mixing hotspots over the vertical turbulent flux in the Southern Ocean Ali Mashayek, Raffaele Ferrari, Jim Ledwell, Sophia Merrifield, Louis St. Laurent Vertical turbulent mixing in the Southern Ocean is believed to play a role in setting the rate of the ocean Meridional Overturning Circulation (MOC), one of the key regulators of the climate system. The extent to which mixing influences the MOC, however, depends on its strength and is still under debate. To address this, a passive tracer was released upstream of the Drake Passage in 2009 as a part of the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES). Vertical dispersion of the tracer was measured in subsequent years to estimate vertical mixing. The inferred effective turbulent diffusivity values have proven larger than those obtained from localized measurements of shear made at various locations along the path of the tracer. While the values inferred from tracer imply a key role played by mixing in setting the MOC, those based on localized measurements suggest otherwise. In this work we employ the tracer data and localized turbulence measurements from DIMES in combination with a high resolution numerical ocean model to investigate whether these discrepancies are the result of different sampling strategies: the microstructure profiles sampled mixing only in a few regions, while the tracer sampled mixing over a much wider area as it spread spatially. [Preview Abstract] 

KP1.00105: Geometrodynamical Fluid Theory Applied to Dynamo Flows in Planetary Interiors Kayla Lewis, Diego Miramontes, Dillon Scofield Due to their reliance on a Newtonian viscous stress model, the traditional NavierStokes equations are of parabolic type; this in turn leads to acausal behavior of solutions to these equations, e.g., a localized disturbance at any point instantaneously affects the solution arbitrarily far away. Geometrodynamical fluid theory (GFT) avoids this problem through a relativistically covariant formulation of the flow equations (Phys. Lett. A 374 347682 (2010)). Using GFT, we derive the magnetohydrodynamic equations describing the balance of energymomentum appropriate for dynamo flows in planetary interiors. These equations include interactions between magnetic and fluid vortex fields. We derive scaling laws from these equations and compare them with scaling laws derived from the traditional approach. Finally, we discuss implications of these scalings for flows in planetary dynamos. [Preview Abstract] 

KP1.00106: INDUSTRIAL APPLICATIONS 

KP1.00107: Pressure cycle rheology of nanofluids at ambient temperature Anoop Kanjirakat, Reza Sadr, Rommel Yrac, Mahmood Amani Colloidal suspensions of particles dispersed in a base fluid (or drilling fluid) are commonly used in oil industry to aid the drilling of oil well into the ground. Nanofluids, the colloidal suspensions of nanosized particles dispersed in a basefluid, have also shown potentials as cooling and abrasive fluids. Utilizing them along with drilling fluids under cyclic highpressure loadings have not been investigated so far. In the present work, rheological characteristics of silicon oil based nanofluids (prepared with alumina nanoparticles) under pressures up to 1000 bar are investigated using a highpressure viscometer. The rheological characteristics of nanofluids are measured and are compared with that of the basefluid under increasing and decreasing pressures. Relative viscosity variations of nanofluids were observed to have influenced by the shear rate. In addition, under cyclic highpressure loading viscosity values of nanofluids are observed to have reduced. This reduction in viscosity at the second pressure cycle could have been caused by the deagglomeration of particles in the first cycle while working a highpressure and highshear condition. [Preview Abstract] 

KP1.00108: JETS 

KP1.00109: ABSTRACT WITHDRAWN 

KP1.00110: Computational analysis for dryice sublimation assisted CO$_{2}$ jet impingement flow SongMi Kwak, Jaeseon Lee The flow and heat transfer characteristics of the novel gassolid twophase jet impingement are investigated computationally. When the high pressure carbon dioxide (CO$_{2}$) flow passes through a nozzle or orifice, it experiences the sudden expansion and the rapid temperature drop occurred by JouleThomson effect. This temperature drop causes the lower bulk jet fluid temperature than the CO$_{2}$ sublimation line, so dryice becomes formed. By using CO$_{2}$ gassolid mixture as a working fluid of jet impingement, it is expected the heat transfer enhancement can be achieved due to the low bulk temperature and the additional phase change latent heat. In this study, 2D CFD model is created to predict the cooling effect of gassolid CO$_{2}$ jet. The gassolid CO$_{2}$ flow is considered by EulerLagrangian approach of mixed phase and the additional heat transfer module is embedded to account for the sublimation phenomena of the solid state CO$_{2}$. The jet flow and heat transfer performance of gassolid CO$_{2}$ jet is investigated by the variance of flow parameter like Reynolds number, solid phase concentration and jet geometries. [Preview Abstract] 

KP1.00111: MAGNETOHYDRODYNAMICS 

KP1.00112: Helical mode interactions and spectral transfer processes in magnetohydrodynamic trubulence Moritz Linkmann, Arjun Berera, Mairi McKay, Julia J\"ager Spectral transfer processes in magnetohydrodynamic (MHD) turbulence are investigated analytically by decomposition of the velocity and magnetic fields in Fourier space into helical modes. Steady solutions of the dynamical system which governs the evolution of the helical modes are determined, and a stability analysis of these solutions is carried out. The interpretation of the analysis is that unstable solutions lead to energy transfer between the interacting modes while stable solutions do not. From this, a dependence of possible interscale energy and helicity transfers on the helicities of the interacting modes is derived. The direction of energy transfer not only depends on magnetic and kinetic helicities but also on the ratio of magnetic to kinetic energy and on the crosshelicity. As expected from the inverse cascade of magnetic helicity in 3D MHD turbulence, mode interactions with like helicities lead to transfer of energy and magnetic helicity to smaller wavenumbers. However, some interactions of modes with unlike helicities also contribute to an inverse energy transfer. As such, an inverse energy cascade for nonhelical magnetic fields is shown to be possible. [Preview Abstract] 

KP1.00113: Finite dissipation and nonuniversality in magnetohydrodynamic turbulence Moritz Linkmann, Arjun Berera, Mairi McKay, Erin Goldstraw, W. David McComb A model equation for the Reynolds number dependence of the dimensionless dissipation rate $C_{\varepsilon}$ in homogeneous magnetohydrodynamic turbulence in the absence of a mean magnetic field is derived from the realspace energy balance equation, leading to $C_{\varepsilon}=C_{\varepsilon, \infty}+C/R_ +O(1/R_^2))$, where $R_$ is a generalized Reynolds number. The constant $C_{\varepsilon, \infty}$ is here defined in terms of the Els\"{a}sser fields and is shown to describe the total energy transfer flux. This flux depends on magnetic and cross helicities, because these affect the nonlinear transfer of energy, suggesting that the value of $C_{\varepsilon,\infty}$ is not universal. Direct numerical simulations for freely decaying and stationary MHD turbulence were conducted on up to $2048^3$ grid points, showing good agreement between data and the model for both cases, different initial values of cross and magnetic helicities and different forcing schemes. The ideas introduced here can be used to derive similar model equations for other turbulent systems. [Preview Abstract] 

KP1.00114: MICROSCALE FLOWS 

KP1.00115: Threedimensional simulation of droplet migration in a HeleShaw microchannel Yue Ling, JoseMaria Fullana, Stephane Popinet, Christophe Josserand Dropletbased microfluidics is a promising tool for performing biomehcanical and chemical assays. Threedimensional simulations are performed in this work to investigate the migration of a droplet in a confined microchannel (a HeleShaw cell). As the droplet moves in the channel, a thin film is formed between the droplet and the wall. The thickness of the film can be two orders of magnitude smaller than the channel height. Furthermore, the time step which is mainly controlled by the surface tension effect becomes very small for low Capillary number. Therefore, numerical simulation of droplet migration in microchannel is challenging. The present simulations are conducted with a twophase flow solver (GERRIS) on an adaptive mesh. The interface between the two phases is captured by the Volumeoffluid method. The droplet dynamics are very different as the aspect ratio (the ratio between the droplet diameter and the channel height) varies from smaller to larger than unity. For droplets of large aspect ratio, the droplet velocity is mainly dictated by the dynamics of the thin film. The simulations also show that the flow around the droplet is three dimensional and has a significant impact on the droplet shape. [Preview Abstract] 

KP1.00116: Hemorheology in PDMS Micro channel with varied surface roughness Bharath Babu Nunna, Shiqiang Zhuang, Eon Soo Lee Hemorheology in micro channel is studied in order to enhance the diagnostic phenomenon of micro assay. Blood consists of formed elements (RBC, WBC {\&} Platelets) and Plasma (Water, Plasma proteins {\&} other solutes). Blood due to existence of RBC will behave as a Non Newtonian fluid. The flow of blood varies on surface roughness of the passage. In this presentation the blood flow characteristics is examined in the micro channel with varied surface roughness on the walls of PDMS micro channels. The micro channel considered for this experiment is fabricated with a cross section close to a rectangular shape with width of 200 $\mu$m1000$\mu$m and depth of 100 um and optically transparent. The analysis of Surface roughness impact on blood flow will help to define and design the micro channel with specified surface treatment on the walls of the channel. [Preview Abstract] 

KP1.00117: Numerical analysis of mixing by sharpedgebased acoustofluidic micromixer Nitesh Nama, PoHsun Huang, Tony Jun Huang, Francesco Costanzo Recently, acoustically oscillated sharpedges have been employed to realize rapid and homogeneous mixing at microscales (Huang, Lab on a Chip, 13, 2013). Here, we present a numerical model, qualitatively validated by experimental results, to analyze the acoustic mixing inside a sharpedgebased micromixer. We extend our previous numerical model (Nama, Lab on a Chip, 14, 2014) to combine the Generalized Lagrangian Mean (GLM) theory with the convectiondiffusion equation, while also allowing for the presence of a background flow as observed in a typical sharpedgebased micromixer. We employ a perturbation approach to divide the flow variables into zeroth, first and secondorder fields which are successively solved to obtain the Lagrangian mean velocity. The Langrangian mean velocity and the background flow velocity are further employed with the convectiondiffusion equation to obtain the concentration profile. We characterize the effects of various operational and geometrical parameters to suggest potential design changes for improving the mixing performance of the sharpedgebased micromixer. Lastly, we investigate the possibility of generation of a spatiotemporally controllable concentration gradient by placing sharpedge structures inside the microchannel. [Preview Abstract] 

KP1.00118: Modeling wrinkledassisted assembly of ordered nanoparticles and nanorods on a wavy substrate Camila Luppi Sato, Peter Yeh, Alexander Alexeev, Martin Mayer, Patrick Probst, Andreas Fery Wrinkleassisted assembly is a technique that allows for fabrication of ordered structures of nanoparticles and nanorods on hydrophilic substrates. As an intermediate step in this process, nanoparticles are deposited within microscopically wrinkled surfaces, where they organize into patterned structures upon solvent evaporation. However, the dependence of the resulting pattern on nanoparticle concentration, particle size and shape, and substrate geometry is not well understood. We develop a model of the ordering process using dissipative particle dynamics (DPD) to predict the resulting nanostructures. We approximate the wavy sheet as a sinusoidal surface. One layer of DPD liquid containing nanoparticles fills the surface, while another layer of DPD fluid acts as the gaseous phase. We model the evaporative process by gradually replacing DPD liquid particles with DPD gaseous particles. The results of our work are useful in designing surface patterns that exhibit strong plasmonic coupling. [Preview Abstract] 

KP1.00119: MULTIPHASE FLOWS 

KP1.00120: Spectral Analysis of Cluster Induced Turbulence Ravi Patel, Peter Ireland, Jesse Capecelatro, Rodney Fox, Olivier Desjardins Particle laden turbulent flows are an important feature of many industrial processes such as fluidized bed reactors. The study of clusterinduced turbulence (CIT), wherein particles falling under gravity generate turbulence in the carrier gas via fluctuations in particle concentration, may lead to better models for these processes. We present a spectral analysis of a database of statistically stationary CIT simulations. These simulations were previously performed using a two way coupled EulerianLagrangian approach for various mass loadings and particlescale Reynolds numbers. The Lagrangian particle data is carefully filtered to obtain Eulerian fields for particle phase volume fraction, velocity, and granular temperature. We perform a spectral decomposition of the particle and fluid turbulent kinetic energy budget. We investigate the contributions to the particle and fluid turbulent kinetic energy by pressure strain, viscous dissipation, drag exchange, viscous exchange, and pressure exchange over the range of wavenumbers. Results from this study may help develop closure models for large eddy simulation of particle laden turbulent flows. [Preview Abstract] 

KP1.00121: NANO FLOWS 

KP1.00122: Electrospinning of Biodegradable and Biocompatible Nanofiber Patches from Solutions of ''Green'' Materials for Plant Protection against Fungi Attack Soumyadip Sett, MinWook Lee, Alexander Yarin, S.M. Alavi Moghadam, Matthias Meinke, Wolfgang Schroeder Biodegradable and biocompatible soy protein/petroleumderived polymer monolithic fibers containing adhesives were electrospun on commercial rayon pads. The polymers used, PVA and PCL, are widely used in the biomedical industry, including such applications as drug delivery and scaffold manufacturing. Soy protein is an abundant waste of SoyDiesel production, and is widely used as a nutrient. The soy content in our fibers was as high as 40 {\%}w/w. Four different adhesives, including ordinary wood glue, repositionable glue and FDAapproved pressuresensitive glue were used for electrospinning and electrospraying. The normal and shear adhesive strengths of the patches developed in this work were measured and compared. The adhesive strength was sufficient enough to withstand normal atmospheric conditions. These biodegradable and biocompatible nanotextured patches are ready to be used on prune locations without being carried away by wind and will protect plants against fungi attack at these locations, preventing diseases like Vine Decline. [Preview Abstract] 

KP1.00123: Nonequilibrium molecular dynamics simulation of the unstirred layer in the osmotically driven flow Keito Konno, Tomoaki Itano, Masako Seki We studied the solvent flows driven by the osmotic pressure difference across the semipermeable membrane. The flow penetrating from the low concentration side transports away solutes adjacent of the membrane, so that the concentration is reduced significantly only at the vicinity of the membrane. It is expected that the relatively low solute concentration develops into a thin boundary layer in the vicinity of the membrane in the case of absence of external stirring process, which is termed as unstirred layer (USL). To investigate concentration distribution in USL, we carried out nonequilibrium molecular dynamics simulations. The flows driven by th osmotic pressure are idealized as 2 dimensional hard disk model, which is composed of solvent and solute molecules. The membrane is modeled as a medium composed of stationary parallel rods distributed by a spatial interval, which is less than the diameter of the solute molecules. The following results were obtained from the numerical simulation. First, the thickness of USL, which was estimated from the obtained concentration distribution, is on the order of a length determined by mean free path. Second, USL was semicircle the center of which is on the end of pore of membrane. [Preview Abstract] 

KP1.00124: NONLINEAR DYNAMICS 

KP1.00125: ABSTRACT WITHDRAWN 

KP1.00126: Finitetime barriers to reaction front propagation Rory Locke, John Mahoney, Kevin Mitchell Front propagation in advectionreactiondiffusion systems gives rise to rich geometric patterns. It has been shown for timeindependent and timeperiodic fluid flows that invariant manifolds, termed burning invariant manifolds (BIMs), serve as onesided dynamical barriers to the propagation of reaction front.~ More recently, theoretical work has suggested that onesided barriers, termed burning Lagrangian Coherent structures (bLCSs), exist for fluid velocity data prescribed over a finite time interval, with no assumption on the timedependence of the flow. In this presentation, we use a timevarying fluid ``wind'' in a doublevortex channel flow to demonstrate that bLCSs form the (locally) most attracting or repelling fronts. [Preview Abstract] 

KP1.00127: ABSTRACT WITHDRAWN 

KP1.00128: NONNEWTONIAN FLOWS 

KP1.00129: Flow of Slurry in the Inclined Closed Channel Nariman Ashrafi Khorasani, Parastoo Piroozram The flow of slurry in a closed inclined circular channel is examined. The viscoelastic fluid is modeled as a derivative of typical OldroydB relation of stress and velocity gradient. First, gravity is considered as the driving force for the fluid flow to simulate the existing sewage system. The complete flow field is evaluated for this case. Next, a pressure gradient is introduced to observe its effects on the flow. Velocity profile as well as stress distributions are given for different scenarios of the nonlinear fluid flowing in a closed channel with and without pressure gradient. [Preview Abstract] 

KP1.00130: MagnetoRheological rotational flow between coaxial cylinders Nariman Ashrafi, Abbas Hazbavi Effects of a magnetic field and fluid nonlinearity are investigated for the rotational flow of a nonlinear viscoelastic fluid following the Carreau model while viscous dissipation is taken into account. The governing motion and energy balance equations are coupled, adding complexity to the already highly correlated set of differential equations. The numerical solution is obtained for the narrow gap limit and steady state base flow. Magnetic field effect on local entropy generation due to steady twodimensional laminar forced convection flow was investigated. This study was focused on the entropy generation characteristics and its dependency on various dimensionless parameters. The effects of the Hartmann number, the Brinkman number, and the Deborah number on the stability of the flow were investigated. Introduction of the magnetic field induces resistive force acting in the opposite direction of the flow, thus causing its deceleration. Moreover, the study shows that the presence of magnetic field tends to slow down the fluid motion. It, however, increases the fluid temperature. Moreover, the total entropy generation number decreases as the Hartmann number and fluid elasticity increase and increases with increasing Brinkman number. [Preview Abstract] 

KP1.00131: POROUS MEDIA FLOWS 

KP1.00132: PIVbased investigation of the skin friction of the flow over random fibrous media Parisa Mirbod, Reza Gheisari Finite Reynolds number (Re\textless 20) flow over fibrous medium inside a rectangular duct was studied using a planar 2D PIV system. Three different fibrous materials with different porosities were used. Fibrous material lined the bottom wall of the duct along the length of the duct. The flow regime for all tests was laminar, and measurements were all done when the flow reached a steady state. Error and uncertainty sources in the experiments were also discussed. Shear rates were estimated at the surface of the fibrous media. As a conclusion to this study skin friction factor were calculated at the interface of all fibrous media at selected Reynolds number. Then using power function, curve fits with the C$_{\mathrm{f}}=$a/Re form were found which could closely correlate skin friction and Reynolds number. To weaken the effect of nearwall errors in estimated shear rates and consequently skin friction, an average of shear rate estimation in a layer with thickness of 5 mm was calculated which was used to calculate an average skin friction. Correlations of average skin friction with average Reynolds number were also presented. [Preview Abstract] 

KP1.00133: ABSTRACT WITHDRAWN 

KP1.00134: Poromechanics modeling of fault stability under the influence of fluid pressure changes Zhibing Yang, Ruben Juanes Fluid injection in a faulted geologic formation can induce slip failure and trigger seismicity. The governing mechanisms are generally explained by the effective stress principle. But it remains unclear how to describe the criterion for the onset of slip failure of preexisting faults in the presence of pore pressure changes. Here we provide a micromechnics perspective by numerical modeling. We first develop a model coupling a discrete element method (for the mechanics of the solid matrix) and porenetwork singlephase flow. Pore pressure provides tractions on the solid grains, changing the mechanical response of the solid material. The fluid pressure distribution is solved via an explicit scheme, taking into account the effect of deformation of the solid matrix. We demonstrate the ability of the twoway coupled poromechanic model to reproduce rock deformation behavior measured in triaxial laboratory tests under the influence of pore pressure. We then study the fault stability in the case of a preexisting impermeable fault, across which there exist a pressure discontinuity due to fluid injection on one side. Numerical results are discussed with a focus on the fault stability criterion and the slip behavior. [Preview Abstract] 

KP1.00135: ABSTRACT WITHDRAWN 

KP1.00136: PARTICLELADEN FLOWS 

KP1.00137: GravityDriven ParticleLaden Flow on an Incline Jesse Kreger, Sarah Burnett, Hanna Kristensen, Andrew Stocker, Jeffrey Wong, Li Wang, Andrea Bertozzi We present experimental results of the height profile of particleladen viscous thin films with finite volume on an incline. For high angles of inclination and high concentrations of mixtures, negatively buoyant particles undergo resuspension then accumulate at the front of the suspending fluid; this leads to the development of a particlerich \lq ridge\rq. Theoretically, the ridge corresponds to the shocks which take on two characteristic shapes: singular and double shocks. We observe the presence of both formations experimentally by varying the volume of the slurry and compare our results to the theoretical model. Our research also investigates the dependence of the fingering instability as the inclination angle or particle to liquid concentration is changed. The slurries have similar dynamics to those used in coating flow techniques and other industrial applications. [Preview Abstract] 

KP1.00138: RAREFIED FLOWS . [Preview Abstract] 

KP1.00139: Molecular dynamics analysis of reflected gas molecules on selfassembled monolayers Hideki Takeuchi In order to investigate the gas flow of high Knudsen number, it is necessary to specify the boundary condition for the reflected gas molecules at a solid surface. In most cases of the analysis, the diffuse reflection is generally assumed, but there are many cases for which this reflection cannot be applied. The characteristics of the reflected gas molecules depend on the state of the solid surface as well as the gassurface interaction. The present author analyzed the scattering properties of monoatomic and diatomic gases on various solid surfaces based on the molecular dynamics (MD) method and proposed the boundary condition of reflected gas molecule (Phys. Fluids 18, 046103, 2006). Recently, selfassembled monolayers (SAMs) for the functionalization of the solid surface have been used in the development of micro/nano devices such as microarray and nanosensor. Therefore, it is interesting to study the scattering behavior of the reflected gas molecules on the SAM surface and make the scattering model of gases for the boundary condition. In this study, the angular distribution and the trapping probability for gas molecule on the SAM surface are observed by using MD simulation. The scattering probability at different incident energies is also discussed. [Preview Abstract] 

KP1.00140: REACTING FLOWS 

KP1.00141: Simulations of SmallScale Liquid Film Combustors Pavel Popov, William Sirignano Recent technological advances have generated need for smallscale combustor designs. The reduction of scale, however, leads to a higher area to volume ratio and thus greater relative heat loss. Liquid film combustors are one proposed design which aims to overcome this obstacle. In them, the fuel is injected as a liquid film on the combustor wall, and heat transfer is reduced due to evaporative cooling of the liquid film leading to reduced temperature gradients at the combustor walls. In this work, we present simulation results for a cylindrical small scale liquid film combustor, in which the reactants are liquid heptane and gaseous air. A computational procedure has been developed to simulate this twophase combustion problem, using detailed chemical mechanisms. A cubic equation of state is applied for the simulation of the gaseous phase at high pressures. The present study examines the structure of the triple flame inside this combustor design, which has been analyzed in previous experimental work. Comparison between simulation and experimental work is made, with particular emphasis on the influence of the chemical mechanism, highpressure equation of state, and the effect of swirl amplitudes in the liquid and gas phases on the structure of the flame. [Preview Abstract] 

KP1.00142: Premixed flame response to pressure fluctuations using an implicit solver with detailed chemistry Nadeem Malik A major challenge in combustion research is the coupling of the compressible flow field to the detailed thermochemistry. Recent advances in numerical solvers has met this challenge within an implicit numerical framework, retaining the full stiffness of the realistic comprehensive chemistry and multicomponent transport properties in the system. Here, the solver TARDIS (Transient Advection Reaction Diffusion Implicit Simulations) [14] is demonstrated, first, by investigating the laminar flame speed in stoichiometric H2/air and CH4/air flames as a function of the flame curvature and found to follow nonlinear regimes, contrary to previous thinking. Second, planar and curved laminar flames are subjected to pressure and equivalence ratio oscillations and found to respond through a spectrum of time and length scales. TARDIS has the potential to elucidate fundamental aspects of flame structure and thermochemistry, and could be the basis for a new generation of implicit DNS solvers. REFERENCES: [1] N. A. Malik, \textit{Combust. Sci. Tech. 182:1011, 17871798 (2012).} [2] N. A. Malik, {\&} R. P. Lindstedt, \textit{Combust. Sci. Tech.} \textit{182:9, 11711192 (2010).} [3] N. A. Malik, {\&} R. P. Lindstedt, \textit{Combust. Sci. Tech. } \textit{184:1011, 17991817 (2012).} [4] N. A. Malik, T. Korokianidis, {\&} T. Lovas. \textit{Submitted, PLOSH ONE, (2015).} [Preview Abstract] 

KP1.00143: SEPARATED FLOWS 

KP1.00144: A Study of Pulsed Blowing Effect on Flow Separation over Flap Yankui Wang, Ping Zhou, Qian Li With the development of the modern aircraft, such as tailless flying configuration, traditional flaps are also the main control surfaces for flight controlling. However, the efficiency of the flap is not only descent quickly due to flow separation over itself under higher deflection angle of flap, but also is evidently influenced by the flow coming down from the upstream wing. A novel flow control technique to improve the flow separation over the flap by pulsed blowing is investigated in this paper by wind tunnel test under Reynolds number of 0.6*10E6 2.4*10E6. To begin with, the control performance for flow separation over the flap is very sensitive to the blowing position and direction and the flow separation can be recovered by the pulsed blowing evidently. Secondly, the pulsed blowing efficiency is 30{\%} higher than that of continuous blowing with the same consumption. In addition, the pulsed blowing efficiency increases quickly with the increasing of pulsed blowing frequency and keep constant gradually when the pulsed blowing Stroul number is bigger than 0.6. [Preview Abstract] 

KP1.00145: SUSPENSIONS 

KP1.00146: Twoscale evolution during shear reversal in dense suspensions Christopher Ness, Jin Sun We use shear reversal simulations to explore the rheology of dense, nonBrownian suspensions, resolving lubrication forces between neighbouring particles and modelling particle contacts as linear springs. The transient stress response to an abrupt reversal of the direction of shear shows rateindependent, nonmonotonic behaviour, capturing the salient features of the corresponding classical experiments. Based on analyses of the hydrodynamic and particle contact stresses and related contact networks, we demonstrate distinct responses at small and large strains, associated with contact breakage and structural reorientation, respectively, emphasising the importance of particle contacts. Consequently, the hydrodynamic and contact stresses evolve over disparate strain scales and with opposite trends, resulting in nonmonotonic behaviour when combined. We further elucidate the roles of particle roughness and repulsion in determining the microstructure and hence the stress response at each scale. [Preview Abstract] 

KP1.00147: TURBULENCE 

KP1.00148: Analytical dampedoscillator models for unsteady atmospheric boundary layers Mostafa Momen, Elie BouZeid Geophysical flows are dynamical systems that are evolving nonlinearly with time. Nonstationary shear and buoyancy forces are the main sources that drive the unsteadiness of such flows. However, due to their inherent complexity, most previous studies focused on steadystate conditions. In these boundary layers, the pressure gradient, buoyancy, Coriolis, and friction forces interact. The mean PDEs governing the unsteady version of the problem, which emerges when these forces are not in equilibrium, are solvable only for a limited set of forcing variability modes, and the resulting solutions are intricate and difficult to interpret. Here we derive a simpler physical model that reduces the governing RANS equations into a firstorder ODE with nonconstant coefficients. The origin of the nonstationarity of turbulence can be buoyant stabilization/destabilization and/or unsteady pressure gradient. The reduced model is straightforward and solvable for arbitrary turbulent viscosity variability, and it captures LES results for linearly variable buoyancy and pressure gradient pretty well. The suggested model is thus general and will be useful for elucidating some features of the diurnal cycle, for shortterm wind forecast, and in meteorological applications. [Preview Abstract] 

KP1.00149: Wake characteristics of a porous square cylinder formed by a multiscale array of obstacles Daniel J. Wise, Pauline Avoustin, Martin Cassadour, Wernher Brevis The characteristics of the flow developed behind arrays of square cylinders are investigated through Particle Image Velocimetry (PIV) and Acoustic Doppler Velocimetry (ADV) measurements in an openchannel water flume. Four arrangements of cylinders are examined: three are multiscale arrays of cylinders based on the Sierpinski carpet fractal, and the fourth is a regular aligned array of single lengthscale cylinders. The porosity, frontal area and external length scale is the same for each cylinder array, while the internal geometry is changed. The relative effect on the dynamics of the wake of the fractal parameters defining the array geometry, such as lacunarity and succolarity is quantified. Special focus is given to the effect of these parameters on the extension and properties of the separated shear layers and on the lowvelocity zone developed downstream the cylinders. [Preview Abstract] 

KP1.00150: Correlation of NearWall Turbulence Structures with Heat Transfer in RibbedPipe Flow Hyungsu Ahn, Changwoo Kang, KyungSoo Yang, Doohyun Park Ribbedpipe flow is one of the most commonly used flow configurations to enhance heat transfer, albeit, at the expense of increased pressure drop. The ribs mounted on the pipe wall differently alter the flow depending on the pitch, the distance between two neighboring ribs. When the pitch is short, fluid is trapped inside grooves, resulting in a low heattransfer rate. When the pitch is long enough, however, the ribs disturb the flow by shedding vortices, resulting in heattransfer enhancement. We aim at elucidating the correlation of nearwall turbulence induced by the shed vortices with the increased heattransfer rate on the ribbedpipe wall. Our analysis is based on our LES data base obtained for Re$=$24,000, Pr$=$0.71, PR(pitch ratio)$=$2, 4, 6, 8, 10, 18, BR(blockage ratio)$=$0.0625. Here, the bulk velocity and the pipe diameter are used as the velocity and length scales, respectively. Our presentation focuses on the nearwall distributions of the higherorder turbulence statistics including but not limited to rms of temperature fluctuation, crosscorrelations, rms of vorticity, and turbulent heat fluxes. Octants and JPDF are also presented in order to clarify the prevailing heattransfer mechanism in the immediate vicinity of the ribbedpipe wall. [Preview Abstract] 

KP1.00151: A numerical and experimental study of anisotropic turbulence in a converging annular duct Junwoo Lim, James Kopriva, Gregory Laskowski, Sara Rostami, Jonathon Slepski, Joshua Szczudlak, Arman Mirhashemi, Scott Morris Large Eddy Simulations of turbulent flow in a converging annular duct has been conducted in support of turbomachinery applications. The experimental rig at University of Notre Dame utilizes wall slot flows to generate temperature profiles representative of a combustor exit upstream of the contraction inlet. A passive turbulence grid is placed just downstream of the profile generator and upstream of the contraction to generate high levels of anisotropic turbulence which is characterized by measurements. The LES runs include both the profile generator and turbulence screen in the analysis to better understand the impact of flow acceleration on vortex stretching for this high level of anisotropic turbulence. An evaluation of the evolution of the anisotropy tensor based on resolved scale will be discussed and comparisons with data will be provided. [Preview Abstract] 

KP1.00152: RankOrdered Multifractal Analysis of Probability Distributions in Fluid Turbulence Chengchin Wu, Tien Chang RankOrdered Multifractal Analysis (ROMA) was introduced by Chang and Wu (2008) to describe the multifractal characteristic of intermittent events. The procedure provides a natural connection between the rankordered spectrum and the idea of oneparameter scaling for monofractals. This technique has successfully been applied to MHD turbulence simulations and turbulence data observed in various space plasmas. In this paper, the technique is applied to the probability distributions in the inertial range of the turbulent fluid flow, as given in the vast Johns Hopkins University (JHU) turbulence database. In addition, a refined method of finding the continuous ROMA spectrum and the scaled probability distribution function (PDF) simultaneously is introduced. [Preview Abstract] 

KP1.00153: Topographic effect on the inclination angle of ramp like structures in rough wall, turbulent channel flow Ankit Awasthi, William Anderson We have studied variation in structural inclination angle of coherent structures responding to a topography with abrupt spanwise heterogeneity. Recent results have shown that such a topography induces a turbulent secondary flow due to spanwisewall normal heterogeneity of the Reynolds stresses (Anderson et al., 2015: J. Fluid Mech.). The presence of these spanwise alternating low and high momentum pathways (which are flanked by counter rotating, domainscale vortices, Willingham et al., 2014: Phys. Fluids; Barros and Christensen, 2014: J. Fluid Mech.) are primarily due to the spanwise heterogeneity of the complex roughness under consideration. Results from the present research have been used to explore structural attributes of the hairpin packet paradigm in the presence of a turbulent secondary flow. Vortex visualization in the streamwisewall normal plane above the crest (high drag) and trough (low drag) demonstrate variation in the inclination angle of coherent structures. The inclination angle of structures above the crest was approximately 45 degrees, much larger than the ``canonical'' value of 15 degrees. Thus, we present evidence that the hairpin packet concept is preserved  but modified  when a turbulent secondary flow is present. [Preview Abstract] 

KP1.00154: VORTEX DYNAMICS AND VORTEX FLOWS 

KP1.00155: Unsteady wake of a rotating tire JeanEloi Lombard, Dave Moxey, Hui Xu, Spencer Sherwin For open wheel racecars, such as IndyCar and Formula One, the wheels are responsible for 40\% of the total drag. For road cars drag associated to the wheels and undercarriage can represent 60\% of total drag at highway cruise speeds. Experimental observations have reported two or three pairs of counter rotating vortices, the relative importance of which still remains an open question, that interact to form a complex wake. Traditional RANS based methods are typically not well equipped to deal with such highly unsteady flows which motivates research into more physical, unsteady models. Leveraging a highfidelity spectral/\textit{hp} element based method a Large Eddy Simulation is performed to give further insight into unsteady characteristics of the wake. In particular the unsteady nature of both the jetting and top vortex pair is reported as well as the time and length scales associated with the vortex core trajectories. Correlation with experimentally obtained particle image velocimetry is presented. [Preview Abstract] 

KP1.00156: Simulating external flow using vortex method in two and three dimensions Henrik Juul Spietz, Mads Mølholm Hejlesen, Jens Honore Walther, Allan Larsen Vortex methods are numerical methods for simulating fluid flow. They use a simple formulation where only the trajectories of discrete vortex particles are simulated. In our method we combine a high order particlemesh based vortex method with an iterative penalization method to simulate external flows around arbitrary geometries such as bridge decks. The method only uses a discretized geometry as input and can easily simulate an arbitrary motion of the geometry. As vorticity is a bounded quantity and the velocity field can easily be calculated for a mixture of freespace and periodic boundary conditions, the method allows for a minimized domain and hence minimal computational resources. However in an external flow problem, vorticity is produced in the boundary layers and transported downstream, consequently the computational domain must grow in time to encapsulate the entire vorticity field. We present a method for truncating this domain by supplementing the freespace and periodic conditions with an outflow condition. The method is conveniently applied within the field of bridge aerodynamics as it can be used for the calculation of the aerodynamic net forces, which depend highly on the geometry and the wake forming behind it. This is demonstrated in 2D and 3D simulations [Preview Abstract] 

KP1.00157: WAVES 

KP1.00158: ~Optimal geometry of an axisymmetric wave energy converter Emma Edwards, Dick K. P. Yue There have been a number of theoretical, experimental and pilotscale studies on wave energy converters with varying shapes and designs, but due to the complex nature of wavebody hydrodynamics, as yet there is not one single threedimensional shape that is agreedupon to be optimal for wave power extraction. Our objective is to determine the optimal geometry to maximize power uptake over a spectrum of incident waves. As an initial investigation, we consider an axisymmetric floating wave power extraction device operating in heave. We assume linear wave conditions. The body geometry is described by smooth polynomial basis functions and is allowed to be completely general, subject to simple constraints. We consider a linear power uptake with a fixed damping coefficient (which could be optimized). For each frequency in the spectrum, hydrodynamic coefficients are calculated using a linear frequencydomain panel method. Then, for a specific incident wave spectrum, maximal extractable power is integrated over the entire spectrum. We will discuss the optimal geometry and associated maximum power for different geometrical constraints and wave conditions. [Preview Abstract] 

KP1.00159: Langmuir Mixing Effects on Global Climate: WAVEWATCH III in CESM Qing Li, Adrean Webb, Baylor FoxKemper, Anthony Craig, Gokhan Danabasoglu, William Large, Mariana Vertenstein Large Eddy Simulations (LES) have shown the effects of ocean surface gravity waves in enhancing the ocean boundary layer mixing through Langmuir turbulence. Neglecting this Langmuir mixing process may contribute to the common shallow bias in mixed layer depth in regions of the Southern Ocean and the Northern Atlantic in most stateoftheart climate models. A third generation wave model, WAVEWATCH III, has been incorporated as a component of the Community Earth System Model, version 1.2 (CESM1.2). In particular, the wave model is now coupled with the ocean model through a modified version of the KProfile Parameterization (KPP) to approximate the influence of Langmuir mixing. Unlike past studies, the windwave misalignment and the effects of Stokes drift penetration depth are considered through empirical scalings based on the rate of mixing in LES. WaveOcean only experiments show substantial improvements in the shallow biases of mixed layer depth in the Southern Ocean. Ventilation is enhanced and low concentration biases of pCFC11 are reduced in the Southern Hemisphere. A majority of the improvements persist in the presence of other climate feedbacks in the fully coupled experiments. [Preview Abstract] 
(Author Not Attending)

KP1.00160: Biological Derived Nanomotors in a ''Domino Fashion'' W.H. Maksoed For disproportionation of H2O2, we also considers an electrokinetic mechanism they appear.So far, the more efficient micro/nanoscale motors are derived from biological systems [2003]. Besides, a control experimenting using 3 stripped Au/Pt/Au rods with catalyzed the composition of H2O2, at a similar rateWalter F Paxton: ``Catalytic Nanomotors,'' JACS, 2004. We also intended to accomaplishes the HCCI quotes from Marcin Frackowiak, dissertation, 2009, just in several characters seems as twin of IGNITION through IceCube document project held since Oct 11, 2001 ever concludes as ``saw none'' so they can be follows the ITER/IFMIF. Refers to S29286 file in UI retrieved: ``magnetic quantumdot cellular automata which is nonvolatile \& lower power consist of nanomagnets. Since they are magnetically coupled, logic can be performed by switching, on the other hand in a DOMINO fashion..'' [A. Klenm: ``Fabrication of Magnetic Tunnel Junctionbased Spintronic Devices..,'' convocation, Aug 1114, 2010. [Preview Abstract] 

KP1.00161: GENERAL FLUID DYNAMICS 

KP1.00162: Separation Analysis in a HighSpeed Rotating Cylinder for a Binary Gas Mixture Sahadev Pradhan, Viswanathan Kumaran The solutions of the species balance equations linked with the generalized Onsager model for the secondary gas flow in a highspeed rotating cylinder are compared with the direct simulation Monte Carlo (DSMC) simulations for a binary gas mixture. The concentration fields are obtained three different types of driving mechanism. These are: (a) wall thermal forcing, (b) inflow/outflow of gas along the axis, and (c) momentum source/sink inside the flow domain, for the stratification parameter $(A)$in the range (0.707 3.535), and Reynolds number (Re) in the range (10$^2$  10$^6$ with aspect ratio (length / diameter) = 2, 4, 8. Two different types of cases have been considered, (a) no mass difference ($\varepsilon_a$ = (2 $\Delta $m/(m$_1$ + m$_2$ )) = 0), and (b) with mass difference ($\varepsilon_a$ = 0.2 and 0.5) while calculating the secondary flow field in the analytical solution. Here, the stratification prameter A = $\surd$((m$_{av} \Omega^2$ R$^2$)/(2 k$_B$ T )), and the Reynolds number Re = $\rho_w \Omega$ R$^2$)/$\mu $, where m is the molecular mass,$\Omega $ and R are the angular velocity and radius of the cylinder, $\rho_w$ is the wall density, $\mu $ is the gas viscosity and T is the gas temperature. The comparison between numerical and analytical solution reveals that the boundary conditions in the numerical simulations and analytical model have to be matched with care. The commonly used ``diffuse reflection'' boundary conditions at the solid walls in DSMC simulations result in a nonzero slip velocity as well as a ``temperature slip'' (gas temperature at the wall is different from wall temperature). [Preview Abstract] 

KP1.00163: Splash Dynamics of Watercolors on Dry, Wet, and Cooled Surfaces David Baron, Ashwin Vaidya, Haiyan Su In his classic study in 1908, A.M. Worthington gave a thorough account of splashes and their formation through visualization experiments. In more recent times, there has been renewed interest in this subject, and much of the underlying physics behind Worthington's experiments has now been clarified. One specific set of such recent studies, which motivates this paper, concerns the fluid dynamics behind Jackson Pollock's drip paintings. The physical processes and the mathematical structures hidden in his works have received serious attention and made the scientific pursuit of art a compelling area of exploration. Our work explores the interaction of watercolors with watercolor paper. Specifically, we conduct experiments to analyze the settling patterns of droplets of watercolor paint on wet and frozen paper. Variations in paint viscosity, paper roughness, paper temperature, and the height of a released droplet are examined from time of impact, through its transient stages, until its final, dry state. Observable phenomena such as paint splashing, spreading, fingering, branching, rheological deposition, and fractal patterns are studied in detail and classified in terms of the control parameters. [Preview Abstract] 

KP1.00164: Premixed Combustion Model for Boron Clouds Mengze Wang, Wang Han, Zheng Chen Boron particle is an ideal additive in solid propellants and fuels due to its very high volumetric heat release. In this study, a premixed combustion model for boron clouds is developed based on a previous combustion model for single boron particle. The flame structure is assumed to be composed of three zones: the preheat zone, the ignition zone, and the reaction zone, and analytical solutions are derived from the governing equations. Consequently the influence of the boron clouds' physical properties on the flame propagation process is investigated. [Preview Abstract] 

KP1.00165: Stability of algebraically unstable dispersive flows Kristina King, Paula Zaretzky, Steven Weinstein, Michael Cromer, Nathaniel Barlow A widely unexplored type of hydrodynamic instability is examined  largetime algebraic growth. Such growth occurs on the threshold of (exponentially) neutral stability. A methodology is provided for predicting the algebraic growth rate of an initial disturbance, when applied to a class of partial differential equations describing wave propagation in dispersive media. There are several morphological differences between algebraically growing disturbances and the exponentially growing wave packets inherent to classical linear stability analysis, and these are elucidated in this study. [Preview Abstract] 

KP1.00166: Janus Gel Fabrication Using Liquid Drop Coalescence and Limited Mixing in the HeleShaw Geometry Brittany Gonzalez, Alexis Moran, Donghee Lee, Sangjin Ryu Hydrogel substrates of tunable stiffness have been actively utilized for in vitro cell mechanobiology study. Here we present a new method to fabricate Janus polyacrylamide gel based on limited mixing between liquid drops coalescing in the HeleShaw geometry. Two prepolymer drops with different concentrations were sandwiched and squeezed between two parallel glass surfaces. Once the drops coalesced in the decreased gap between the surfaces, gelation was initiated by UV light exposure with various time delays. AFM nanoindentation was utilized to map the Young's modulus of obtained gels. Fabricated Janus gels had two regions of different Young's moduli interfaced by the stiffness gradient zone, and the width of the gradient zone increased with the delay time. [Preview Abstract] 

KP1.00167: Metastable states of rigid bodies in a flow. Ashwin Vaidya, Doralia Castillo, Matt Cristaldi, Bongjae Chung, Karina Soriano, Haiyan Su Symmetric bodies such as cylinders and spheroids, in their terminal stable states, are long known to have their long axis align themselves perpendicular to the direction of flow. This property has been confirmed in sedimentation and horizontal flow setup and the transition to a terminal stable state is believed to coincide with the onset of significant inertial effects in the flow. However, the threshold at which this transition occurs is yet unknown. In this presentation we report a recent experimental study to examine the nature of the transition of prolate spheroids and cylinders of various aspect ratios, from initial to their terminal stable equilibrium. Our experiments reveal that the body reconfigures itself from its initial orientation, continuously to an angle perpendicular to the flow direction, revealing possible steady intermediate angles. Are these ``metastable states'' real or an artifact of our experiments? Experiments performed on a variety of bodies and using different suspension mechanism show this state to be persistent. A three dimensional numerical simulations performed by us provide strong support for these observations and reveals interesting new findings about the nature of the torque imposed on the body due to the flow at changing Reynolds numbers. [Preview Abstract] 

KP1.00168: Mass flow rate of granular material flowing from tilted bins Jaime Klapp, Abraham Medina, Ayax Hernando Torres Victoria, Salomon Peralta Lopez We report experiments performed to describe the behavior of the experimental mass flow rate of cohesionless granular material, $M^{'}_{\beta expt} $, through circular orifices of diameter $D$ made on sidewalls of tilted bins. In such experiments, the influence of the wall thickness of the bin, $ w $, and the tilt angle respect to the vertical, $\beta$, were also regarded. The experimental measurements, using beach sand and granulated sugar, yield a linear correlation among $ M^{'}_{\beta expt} $ and a theoretical piecewise correlation of the mass flow rate, $ M^{'}_{\beta} $, which is valid for the overall range of values of $\beta$. Numerical simulation will be also a discussed. [Preview Abstract] 

KP1.00169: Capillary rise in a tilted TaylorHauksbee cell Abraham Medina, Jaime Klapp, Ayax Hernando Torres Victoria, Salomon Peralta Lopez, Aydet Jara Hernandez The penetration of a wetting liquid in the narrow gap between two tilted plates making a small angle among them is analyzed in the framework of the lubrication approximation. At the beginning of the process, the liquid rises independently at different distances from the line of intersection of the plates. The maximum height of the liquid initially increases as a power law of time, where the exponent is dependent on the angle of inclination of the plates and is attained at a point that reaches the line of intersection only after a certain time. At later times, the motion of the liquid is confined to a thin layer around the line of intersection whose height increases again as a power law of time and the exponent of the power law is a function of the angle of inclination. The thickness of the film decreases as the inverse of the power law of time. The evolution of the liquid surface is computed numerically and compared with the results of simple experiments. [Preview Abstract] 

KP1.00170: Development of Schlieren Imaging for Analysis of Supersonic Complex Multistream Rectangular Nozzle Thomas Coleman, Matthew Berry, Andrew Magstadt, Sivaram Gogineni, Mark Glauser A schlieren apparatus has been installed to provide the shock structure of the flow in a supersonic complex multistream rectangular jet nozzle. The schlieren images collected are being used for analysis which is paired with unsteady pressure data taken simultaneously, both of which complement PIV data taken in same facility. The schlieren setup is of Herschellian ztype configuration aligned vertically and perpendicular to the nozzle exit. By making use of large twin parabolic mirrors, a 12.5 inch diameter test window has been achieved, capable of capturing the evolution of shock cells from development to collapse. An LED light source was used with its driver circuit to allow for controlled microsecond pulses for collecting time resolved schlieren. Schlieren results to date indicate that there is a shock train arising inside the nozzle and persisting downstream that is quasi steady. This has also been observed in simulations. The shock structure appears to have a dominant effect in that they localize and provide the skeleton for the other flow structures, affecting and being affected by the adjacent shear layers. [Preview Abstract] 

KP1.00171: Reduction of aerodynamic load fluctuation on wind turbine blades through active flow control JohnMichael Velarde, Thomas Coleman, Andrew Magstadt, Somil Aggarwal, Mark Glauser The current set of experiments deals with implementing active flow control on a Bergey Excel 1, 1kW turbine. The previous work in our group demonstrated successfully that implementation of a simple closedloop controller could reduce unsteady aerodynamic load fluctuation by 18{\%} on a vertically mounted wing. Here we describe a similar flow control method adapted to work in the rotating frame of a 2.5m diameter wind turbine. Strain gages at the base of each blade measure the unsteady fluctuation in the blades and pressure taps distributed along the span of the blades feed information to the closedloop control scheme. A realistic, unsteady flow field has been generated by placing a cylinder upstream of the turbine to induce shedding vortices at frequencies in the bandwidth of the first structural bending mode of the turbine blades. The goal of these experiments is to demonstrate closedloop flow control as a means to reduce the unsteady fluctuation in the blades and increase the overall lifespan of the wind turbine. [Preview Abstract] 

KP1.00172: Investigation of RichtmyerMeshkov turbulent mixing using front tracking method Dan She, Hyunkyung Lim, Pooja Rao, James Glimm Simulations are performed to study mach number and initial conditions effects on RichtmyerMeshkov (RM) mixing. In a long shock tube ($12.7 cm \times 12.7 cm \times 639.6 cm$), a perturbed interface between airacetone and SF6 ($A=0.64$) is accelerated in the simulation. Two kinds of RM initial conditions (linear and nonlinear) and two Mach numbers (1.3 and 1.45) are set in simulations. Front tracking method is used to decrease numerical diffusion around the interface. Initial conditions come from experiments measured by Los Alamos National Laboratory. Simulation results are compared with experiment results. [Preview Abstract] 

KP1.00173: The Fluid Mechanics of the Bible: Miracles Explainable by Christian Science? Amy Lang The Bible is full of accounts clearly in violation of our scientific understanding of fluid mechanics. Examples include the floating axe head, Jesus walking on the water and immediately calming a storm. ``Jesus of Nazareth was the most scientific man that ever trod the globe. He plunged beneath the material surface of things, and found the spiritual cause," wrote Mary Baker Eddy (18211910), the founder of a now wellestablished religion known as Christian Science, in her seminal work Science {\&} Health with Key to the Scriptures. She asserted that Jesus' miracles were in accord with the, ``Science of God's unchangeable law.'' She also proclaimed that matter is a derivative of consciousness. Independently with the discovery of quantum mechanics, physicists such as Max Planck and Sir James Jeans began to make similar statements (``The Mental Universe'', Nature, 2005). More recently, Max Tegmark (MIT) theorized that consciousness is a state of matter (New Scientist, April 2014). Using a paradigm shift from matter to consciousness as the primary substance, one can scientifically explain how a mental activity (i.e. prayer) could influence the physical. Since this conference is next door to the original church of Christian Science (Const. 1894), this talk will discuss various fluidmechanic miracles in the Bible and provide an explanation based on divine metaphysics while providing an overview of scientific Christianity and its unifying influence to the fields of science, theology and medicine. [Preview Abstract] 
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