Research
Theoretical Fluid Dynamics
My Research interests lie primarily in analytical fluid dynamics. My main focus is on the theory of traffic flow, in which the motion of cars on a roadway is compared to that of a fluid stream. I am also interested more broadly in hyperbolic conservation laws and collective dynamics. More recently, I have become interested in second order macroscopic models for traffic flow (such as the Aw-Rascle-Zhang model), in which the density and velocity of traffic each have their own (coupled) dynamics. Click below to read a paper I co-authored with my advisor, Dr. Changhui Tan, regarding analysis of first order nonlocal macroscopic models.
(Scientific) Machine Learning
Recently, I have become invested in applying deep learning techniques to PDE's. Specifically, I'm interested in applying physics-informed deep learning models to local and nonlocal DE's arising from continuum mechanics, especially as it pertains to formulating robust and accurate traffic flow models. I use deep learning for traffic state estimation (TSE) and equation discovery.
In 2022, I was appointed as a graduate student instructor for the Summer School on Mathematical Foundation of Data Science at USC, supported by the NSF RTG grant. I worked with Dr. Wuchen Li and six undergraduate mathematicians on a problem of maximum likelihood estimation via Wasserstein natural gradient descent algorithms.
Computational Fluid Dynamics
During summer 2023, I served as a graduate student intern at UMD ARLIS. With guidance from Dr. James Baeder, our team used machine learning to improve CFD solvers for the Spalart Allmaras (SA) turbulence closure model for Reynolds-Averaged-Navier-Stokes (RANS) equations. While turbulence models for RANS are attractive compared to computationally intractable direct numerical simulation (DNS), current turbulence models perform poorly when adverse pressure gradients (e.g. separated flow) is present. We used Field-Inversion-Machine-Learning (FIML) to produce a neural network correction to the SA model by modifying the turbulence production term. In house mesh generation and flow solvers were computed using the UMD Zaratan HPC cluster (80 Nvidia A100 GPUs!). For the FIML step, adjoint methods are used to compute gradients.
Figure: One sees a recirculating flow in the separated flow region. The nlf-0416 airfoil is experiencing stall due to high angle of attack (20 degrees). SA turbulence model is inaccurate in quantifying loss of lift owing to this phenomenon.
Conferences, Workshops, and Seminars
09/18/2021 44TH SIAM-SEAS conference, Auburn University
Contributed presentation: On a Class of Nonlocal Macroscopic Traffic Models.
WINNER: Best Presentation Award.
09/24/2021 ACM Student Seminar, University of South Carolina
Talk: Hyperbolic Conservation Laws and Nonlocal Traffic Flow Theory
04/22/2022 ACM Student Seminar, University of South Carolina
Talk: Uniqueness of Entropy Solutions for Scalar Conservation Laws.
06/28/2022-06/29/2022 Partners for Minorities in Engineering and Computer Science
Senior precalculus workshop
09/28/2022 ACM Student Seminar, University of South Carolina
Talk: Traffic flow - Nonlocal to Local Solutions
10/25/2022 PME and Gamecock Math Club (undergraduate math club), University of South Carolina
Talk: A 'Crash' Course on the Mathematics of Traffic Flow
11/12/2022 40th Southeastern-Atlantic Regional Conference on Differential Equations, NC State University
Contributed presentation: Sharp Critical Thresholds for a Class of Nonlocal Traffic Flow Models
01/25/2023 Graduate Colloquium, University of South Carolina
Talk: Fluid Dynamics: Scalar Balance Laws for Traffic Flow
03/17/2023 AMS Sectional Meeting, Georgia Tech