Bulletin of the American Physical Society
75th Annual Meeting of the Division of Fluid Dynamics
Volume 67, Number 19
Sunday–Tuesday, November 20–22, 2022; Indiana Convention Center, Indianapolis, Indiana.
Session G08: Boundary Layers: General I |
Hide Abstracts |
Chair: Amirhossein Arzani, University of Utah Room: 135 |
Sunday, November 20, 2022 3:00PM - 3:13PM |
G08.00001: Solving thin boundary layer problems with physics-informed machine learning inspired by perturbation theory Amirhossein Arzani, Kevin W Cassel, Roshan M D'Souza Thin boundary layers commonly arise in high Reynolds number flows and high Peclet number convective transport. An accurate numerical solution to these problems requires a high-resolution mesh near the wall. In the case of high Schmidt number mass transport that commonly arises in biotransport problems, the extremely thin nature of these boundary layers makes traditional numerical solution a tedious task. Modern scientific computing approaches such as physics-informed neural networks (PINN) provide an alternative mesh-free strategy. However, PINN cannot resolve the sharp gradients in thin boundary layers. In this talk, we present a boundary-layer PINN (BL-PINN) approach inspired by the classical perturbation theory. We demonstrate how PINN architecture could be designed in a theory-guided fashion to replicate the singular perturbation theory using asymptotic expansions. In benchmark convective transport problems, we demonstrate that BL-PINN can solve thin boundary layer problems with good accuracy. We also discuss parametric re-evaluation of the solution in BL-PINN without the need for retraining. Finally, we leverage the hybrid data-driven and physics-based framework offered by PINN to demonstrate the utility of BL-PINN for solving inverse problems in boundary layers. |
Sunday, November 20, 2022 3:13PM - 3:26PM |
G08.00002: Boundary-layer flow of air induced by a falling soap film Yuna Hattori, Kalale Chola, Julio Barros Jr., Christian Butcher, Rory Cerbus, Pinaki Chakraborty In a soap-film channel, the soap film is embedded in the surrounding air. The falling film drags the air, inducing it to flow in a thin layer adjacent to the film. This flowing air, in turn, resists the motion of the falling film; thus, the film-air interface is a dynamic boundary. We measure the airflow velocity profile in this interface's boundary layer using super-resolution Particle Image Velocimetry. We find that the downstream evolution of the air velocity profile manifests self-similarity, which we analyze using the framework of the boundary-layer theory. Beyond air-film interaction, our findings may bear on a broader class of flows over dynamic boundaries, e.g. ocean-air interaction. |
Sunday, November 20, 2022 3:26PM - 3:39PM |
G08.00003: A numerical investigation of the flow around a flat plate at zero incidence up to a Reynolds number of 5·105. Shaiyan Rahman, Nikolaos A Malamataris The flow around a flat plate at zero incidence is studied as a numerical experiment with an in-house code. The Reynolds number varies from 0.1 up to 5·105. Although the flow has been studied extensively for more than hundred years, there are still issues unresolved. First of all, there is no single laboratory experiment that studies how the skin friction along the flat plate varies in the whole range of the Reynolds numbers. Some of the most notable studies on this subject are limited either in the range from 30 < Re < 2500 or from 1·105 < Re < 5·105. To the best of our knowledge, there is no single numerical experiment that can either verify these results or claim anything different. In addition, there is the issue with the transverse component of the velocity of this flow which has never been a subject of study so far in all attempts to verify the boundary layer theory related to this case. This work attempts to fill this gap by performing an appropriate numerical experiment. The numerical method for the solution of the Navier Stokes is finite elements. Parallel computing is absolutely necessary for this research, since more than 90 millions unknowns are involved. The flow is studied both with and without pressure gradient, in order to investigate the difference in the results. |
Sunday, November 20, 2022 3:39PM - 3:52PM Author not Attending |
G08.00004: Numerical simulation of spiral vortices on rotating sphere Masaya Muto, Makoto Tsubokura, Ryoichi Kurose Flow characteristics and fluid force on a sphere rotating along with an axis parallel to mean airflow were investigated using Large Eddy Simulation at around critical Reynolds numbers of 200,000. As a result of the simulation, a decrease in the numbers of spiral vortices and striped pressure distributions on the sphere were visualized depending on the rotation speed of the sphere even though the sphere is exposed to the same Reynolds number condition. Also, as the rotation speed of the sphere increased, the relative velocity between the mean flow and the surface of the sphere increased, subsequently, the length of the spiral vortex decreased due to the boundary layer transition on the sphere's surface. The shift of the separation point depending on the rotation speed is also discussed from the viewpoint of this boundary layer transition on the surface. |
Sunday, November 20, 2022 3:52PM - 4:05PM |
G08.00005: Temperature scaling for high-Mach-number flows above adiabatic walls Peng Chen, George P Huang, Yipeng Shi, Xiang F Yang, Yu Lv The mean velocity follows a logarithmic scaling in the surface layer when normalized by the friction velocity, i.e., a velocity scale derived from the wall-shear stress. |
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. |
© 2024 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