Bulletin of the American Physical Society
77th Annual Meeting of the Division of Fluid Dynamics
Sunday–Tuesday, November 24–26, 2024; Salt Lake City, Utah
Session A01: Minisymposium: Fluids Next - Fluid Dynamics in Advanced Medicine |
Hide Abstracts |
Chair: Jessica Shang, University of Rochester Room: Ballroom A |
Sunday, November 24, 2024 8:00AM - 8:26AM |
A01.00001: Modelling cerebrospinal fluid dynamics in a mouse brain Invited Speaker: Kimberly A Boster The flow of cerebrospinal fluid (CSF) in the in the brain plays an important role in clearance of waste and is linked to diseases such as Alzheimer’s and small vessel disease. We use physics informed neural networks (PINNs) to infer in vivo flow fields. This presentation describes various modelling and experimental efforts aimed at understanding the fluid dynamics of CSF flow. Specifically, we use PINNs to infer high-resolution pressure, volumetric flow rates, and shear stresses of CSF in tens-of-micron-scale channels from sparse two-dimensional (2D) velocity measurements and three-dimensional (3D) domain boundaries. We also use PINNs to infer brain-wide CSF flow from dynamic contrast-enhanced magnetic resonance imaging, which captures time-evolving concentration fields. Our approach includes the advection diffusion equation in the loss function, thus enforcing the physics. The neural network also learns the how the brain tissue permeability varies throughout the brain. We validate the approach using synthetic data from a realistic brain geometry with a realistic distribution of permeability values spanning several orders of magnitude, and we also show model predictions of flow and permeability from real data. |
Sunday, November 24, 2024 8:26AM - 8:52AM |
A01.00002: Cavitation dynamics and damage in soft matter Invited Speaker: Eric Johnsen The collapse of vapor bubbles in water has long been studied and known to damage neighboring solid objects in applications ranging from naval hydrodynamics to turbomachinery. With the development of ultrasound therapies, there has been increasing interest in investigating the behavior of cavitation bubbles in soft materials, particularly in the medical context. The rheology of soft matter introduces additional physical effects (e.g., elasticity, relaxation), whose effects are not fully understood due to the complexity of the microstructure. In this presentation, we will discuss our efforts to model cavitation-bubble dynamics in soft matter and highlight some of their distinctive features, motivated by two specific applications: histotripsy (a novel ultrasound therapy to homogenize human tissue) and blast-induced traumatic brain injury. |
Sunday, November 24, 2024 8:52AM - 9:18AM |
A01.00003: Simulating blood flow in the frequency domain Invited Speaker: Mahdi Esmaily Flow dynamics in the respiratory system or the blood flow in the human body caused by the rhythmic beating of the heart are inherently time-periodic phenomena. In this talk, I discuss the possibility of simulating these flows in the time-spectral (frequency) domain. I argue that such a shift in formulation can present a significant advantage over conventional methods that are formulated in time. I demonstrate this point through a realistic blood flow modeling problem, where I show the flow is well-approximated using a handful of Fourier modes. That small number, when compared to thousands of time steps required in a conventional CFD solver, implies orders of magnitude reduction in the number of computed unknowns. The result is a method that reduces the cost of a typical cardiorespiratory simulation from days to hours. I briefly discuss how a finite element method can be constructed to solve the Navier-Stokes equations in the frequency domain. That includes introducing a method that remains stable in strongly convective flows while maintaining computational efficiency in solving a large coupled system of nonlinear equations. |
Sunday, November 24, 2024 9:18AM - 9:44AM |
A01.00004: The influence of transient physiological factors on patient-specific cerebral aneurysm hemodynamics Invited Speaker: Melissa Brindise Hemodynamic factors are known to play a critical role in the growth and rupture of an intracranial aneurysm (IA). However, conflicting findings regarding the specific role of individual flow parameters have been reported, suggesting confounding factors not considered among studies to date may exist. Current studies, regardless of the modality used, consider aneurysmal flow fields only from a single, fixed set of inflow conditions, typically assumed by or based on in vivo 4D-Flow magnetic resonance imaging (MRI) data. However, IAs inherently exist within a dynamic system, and are subject to transient factors. For example, changes in the patient’s vitals alter aneurysmal inflow conditions; the aneurysm is rotated depending on if the patient is standing, laying down, or moving actively; etc. It is not clear the extent to which these factors alter aneurysmal hemodynamics or affect IA progression. In this work, we address this question. Using 4D particle tracking velocimetry (PTV), we evaluate how changes to heart rate, blood pressure, and aneurysm orientation affect hemodynamic factors affect the flow in patient-specific IA geometries. We also evaluate how vessel compliance may affect IA hemodynamics. Flow parameters known to influence aneurysm progression including wall shear stress (WSS), oscillatory shear index (OSI), flow complexity, and high-frequency velocity fluctuations are evaluated across the varying physiological conditions. Overall, through this analysis, we comment on the extent to which transient physiological factors must be considered when studying IA flow and risk of progression as well as if these factors may have contributed to the conflicting results reported to date. |
Sunday, November 24, 2024 9:44AM - 10:10AM |
A01.00005: Advancing Voice Health: High-Fidelity Modeling of Human Voice Production from Neuromuscular Control to Acoustic Resonance Invited Speaker: Qian Xue The human voice produces a remarkably diverse array of sounds, making it the primary channel for human communication and a potential interface for human-computer interaction. Voice production starts with neural stimulation of the intrinsic laryngeal muscles, which control the position and biomechanics of the vocal folds. Air from the lungs interacts with the vocal folds, generating self-sustained vibrations and creating a pulsatile jet in the larynx. These glottal air pulses form the primary sound sources, which pass through the supraglottal vocal tract, reshaping the sound spectrum as an acoustic resonator. This intricate process requires precise neuromuscular control of complex interactions among glottal flow dynamics, vocal fold vibrations, and vocal tract acoustics. |
Sunday, November 24, 2024 10:10AM - 10:36AM |
A01.00006: Transport and targeting of pulmonary inhalation aerosols: mechanistic lessons from the deep lungs Invited Speaker: Josue Sznitman Mapping respiratory airflows and the transport mechanisms of inhaled aerosols characteristic of the deep regions of the lungs are of broad interest in assessing inhalation therapy outcomes. In the present talk, I will discuss our current understanding of such phenomena characterized by sub-millimeter 3D alveolated airspaces and low-Reynolds-number flows. I will exemplify advances brought forward by experimental efforts, in conjunction with numerical simulations, to revisit past mechanistic theories of respiratory airflow and particle transport, emphasizing the coupled roles of convection, diffusion, sedimentation and most recently electrostatics. I will highlight how microfluidics spanning the past decade have accelerated opportunities to deliver anatomically-inspired models that capture with sufficient realism and accuracy the leading mechanisms governing respiratory airflow and aerosol transport at true scale. Such efforts have provided previously unattainable in vitro quantifications on the local transport properties in the deep pulmonary acinar airways, with new paths to resolve mechanistic interactions between airborne particulate carriers and respiratory airflows at the pulmonary microscales. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2025 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700