Bulletin of the American Physical Society
76th Annual Meeting of the Division of Fluid Dynamics
Sunday–Tuesday, November 19–21, 2023; Washington, DC
Session T40: Reacting Flows: Detonations and DDT II 
Hide Abstracts 
Chair: Matei Radulescu, University of Ottawa Room: 204C 
Monday, November 20, 2023 4:25PM  4:38PM 
T40.00001: Exploring Porosity Models for PBX 9501 Bradford A Durant, Matthew Price, Andrew K Henrick, Tariq D Aslam High explosive's (HE) performance such as rundistance and time to detonation has observable differences when the porosity changes. Current efforts to model such discrepancies involve calibrating equation of state (EOS) parameters using an averaged density of all the HEs experimental data used for the calibration. One such idea to make a porosity aware model is to use a hybrid Palpha and smalllambda model. This approach uses a porosity model known as Palpha along with the Davis reactants EOS at nominal density along with a known initial porosity. A fully compacted EOS is constructed, then different initial densities are considered as equilibrium mixtures of the fully compacted reactants with varying small amounts of Davis products. This work involves investigating the combined effect of the Hugoniot of this mixture model, along with the effects of burn rate models to the material response of various impact particle speeds. Available gasgun experimental data will be used to compare the material response metrics such as rundistance and time to detonation given by this hybrid model. 
Monday, November 20, 2023 4:38PM  4:51PM 
T40.00002: ShockFitting using HamiltonJacobi Solver for High Order Solutions of Curved Detonation Andrew K Henrick Detonation front shape and phase speed are characteristic properties used to experimentally quantify the performance of High Explosives (HEs). Reactive burn models such as AWSD are also calibrated using these shot data as collected from charges in multiple standard geometries. Thus, HE simulation and calibration require accurate solutions at the propagating detonation front. Shock capturing and adaptive mesh refinement methods are limited to first order convergence in approximating such discontinuous solutions. Shockfitting is a technique which effectively removes the leadshock discontinuity, again making high order convergence possible. Here a new variation of shockfitting method is presented which directly solves the HamiltonJacobi equation describing the detonation front, yielding the shock shape and speed to high order. The high order convergence of the method is verified using an exact solution for a polytropic gas with a depletion reaction rate. Solution validation is made using diameter effect data for a number of conventional HEs. Comparison with previous variations of the shockfit algorithm are also given. 
Monday, November 20, 2023 4:51PM  5:04PM 
T40.00003: InductionZone Behavior in Different Fuels in Rotating Detonation Engine Combustion Yongqi Y Zhao, Foluso Ladeinde, Wenhai Li Rotating Detonation Engines (RDEs) have been studied extensively, particularly in recent years, with the motivation coming from the promise of superior propulsive performance in highspeed flight. A significant amount of the research efforts in this area has been based on using hydrogen as the fuel. In general, hydrocarbon fuels such as methane, acetylene, and ethylene, are more difficult to detonate than hydrogen because of their lower flammability. Therefore, it is expected that the inductionzone behavior of different fuels will vary based on their chemical properties and combustion characteristics. The inductionzone in the specific case of a detonation wave refers to the region where the fueloxidizer mixture is at a relatively low temperature, which is located after the shock wave, but before the point of thermal runaway, which defines the location of the flame. The objective of this study is to investigate the inductionzone behaviors of different fuels used in a model of the RDE combustor. This knowledge will enable better decisions in fuel selection. A largeeddy simulation solver will be used for the analysis. The characteristics of the induction zone, including its length, temperature, and fueloxidizer mixture composition, are expected affect the overall propulsive performance and efficiency of the RDE. 
Monday, November 20, 2023 5:04PM  5:17PM 
T40.00004: LaserInduced Combustion and Shock Wave Expansion Dynamics of Energetic Metal Particles Binit singh, Sayan Biswas

Monday, November 20, 2023 5:17PM  5:30PM 
T40.00005: The critical conditions for the formation of the Mach shock from shock reflections Farzane Zangene, Matei Radulescu The goal of this study is to determine the critical conditions for the generation of a detonation wave from shock reflections. This objective is achieved by implementing a novel technique of convergingdiverging nozzle, inspired by White (1963). In this method by propagating the detonation wave in the converging section, it will be overdriven, and the cellular instability will be reduced to a smaller scale. In the diverging section, the detonation wave restores a quasilaminar structure, consisting of a leading shock wave followed by a reaction wave. The interaction of the two decaying incident shocks generates a Mach reflection. To identify the local conditions of the formation and determine the role of the dynamics of reflecting shocks the controlling parameters are systematically changed. The critical conditions were found to closely correspond to the condition where the time scale of gas expansion behind the resulting Mach shock is comparable with the ignition delay time. 
Monday, November 20, 2023 5:30PM  5:43PM 
T40.00006: Numerical investigations of detonation cell sizes in hydrogenmethane fuel blends Milin Martin, Elaine S Oran, Ashwath Sethu Venkataraman

Monday, November 20, 2023 5:43PM  5:56PM 
T40.00007: Some thoughts on colliding reactive fuel droplets in a supersonic combustion field Foluso Ladeinde Liquidfuel droplets in an environment of atmospheric air at supersonic speeds characterize the early stage of fuelair mixture in highspeed combustion systems intended for devices that propel air vehicles. Examples of these devices include the scramjet and rotating detonation engines. Modeling the reactive system occurs at different levels of complexity. In the simplest form, the inertia of the droplets is weak, the droplets do not collide, and the only velocities involved are those of the continuous phase (with turbulence fluctuations) and the rigidsolid velocities of the droplets. The limit in which the droplets collide, though without coalescence, is of interest in the present study, with an additional velocity component that arises from the microscopic field surrounding a droplet. For this component, previous research, particularly in atmospheric science, has assumed the dominance of viscosity in the environment surrounding the droplet, such that the solution of a Stoke’s flow around the droplet is obtained to represent the velocity field in the ambient of the particle. By a judicious application of boundary conditions, this field is made to be compatible with the velocity field of the continuous phase. In this manner, the net velocity that appears in the equation for the dispersed phase has contributions from the four components of velocity. The problem of our interest differs from the foregoing in the sense that a mathematically hyperbolic system obtains, as opposed to the elliptic limit of the Stokes problem. Our approach is to obtain a solution of the hyperbolic flow problem that is consistent with the velocity field of the continuous phase. The implication of this approach for the flow and chemical reaction processes, and hence the power and efficiency of a highspeed propulsive device is what we seek to investigate. Preliminary results along this direction will be reported. 
Monday, November 20, 2023 5:56PM  6:09PM 
T40.00008: Unstable gaseous detonations as a deterministic paradigm for SelfOrganized Criticality Matei Radulescu, Aliou Sow We study the nonlinear dynamics of galloping unstable detonations, characterized by a complex sequence of initiation and failure. We analyze the timeseries of the lead shock obtained numerically over very long periods. Calculations are reported for the reactive Euler equations and the reduced Fickett reactive Burgers equation model. The detonation speed dynamics develop an approximate selfsimilar power law scaling, with a power spectrum scaling like $1/f$ over at least one decade of scales. This is characteristic of SelfOrganized Criticality (SOC), i.e., the scalefree organization of the dynamics on large scales with no characteristic time, shared by many systems in nature governed by avalanchelike dynamics for energy release (e.g., earthquakes, evolution, sandpile avalanches, droplet coalescence). We argue that detonations offer a unique deterministic paradigm to study SOC in avalanche dynamics and inverse energy cascades. We discuss the organization of the detonation front dynamics in terms of the physics controlling the wave front evolution. It is found that the largest "avalanches" trigger the longest lived shock relaxation by the gasdynamic relaxation, involving the expansion wave catching up to the front. Instability in the decaying front triggers a hierarchy of smaller avalanches superposed on the larger ones in a fractallike structure. These dynamics are discussed in the context of our earlier high order nonlinear oscillator model (Bellerive, ICDERS 2016). 
Follow Us 
Engage
Become an APS Member 
My APS
Renew Membership 
Information for 
About APSThe American Physical Society (APS) is a nonprofit membership organization working to advance the knowledge of physics. 
© 2024 American Physical Society
 All rights reserved  Terms of Use
 Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 207403844
(301) 2093200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 5914000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 200452001
(202) 6628700