University of Texas at Austin

Past Event: Babuška Forum

Recent developments in numerical methods for Brownian suspensions of complex rigid particles

Yuanxun Bao, Postdoctoral Fellow, Oden Institute, UT Austin

10 – 11AM
Friday Apr 12, 2019

POB 6.304

Abstract

Recent advances in colloidal synthesis allow the control of particle shape and open new opportunities to explore colloidal self-assembly at a higher level of complexity. Numerical simulations are particularly suitable for exploring effects of shape asymmetry on the collective behavior of colloidal systems without fabricating the particles in the first place. In chemical engineering, the methods of Brownian and Stokesian Dynamics are popular but limited to spherical particles only. In this talk I will present new progresses in the numerical methods for simulating colloidal suspensions of complex rigid particles beyond spheres. I will present fast methods that address the following challenges: (1) incorporating the long-ranged many-body hydrodynamic interactions in the presence of viscous fluid; (2) consistently generating the hydrodynamically correlated Brownian motion; (3) achieving (near-) linear scaling as the number of particles increases. In the first part of the talk, I will present a relatively low-accuracy but flexible and simple rigid multiblob method that is based on the immersed boundary method and Stokes equation. Experimentally-relevant configurations such as no-slip walls and confinement can be implemented as boundary conditions in the fluid solver. Thermal fluctuations and thus Brownian motion can be consistently modeled by including a stochastic stress in the momentum equation, as dictated by fluctuating hydrodynamics. In the second part, I will present a resolved and high-accuracy fluctuating boundary integral method for Brownian suspensions. For both methods, I will focus on developing (near) linear-scaling algorithms for generating both the deterministic and stochastic (Brownian) contributions of the particle velocities. Bio Dr. Yuanxun Bao received his Ph.D. in Mathematics from the Courant Institute of Mathematical Sciences, New York University in 2018. His research interests are in the areas of multiscale computational modeling of fluids and materials science. In particular, he is interested in developing computational methods for studying physical and biological systems where stochastic effects are important. His current work at ICES is under the supervision of Professor George Biros, and focuses on the simulation, optimization and design under uncertainty in materials science.

Event information

Date
10 – 11AM
Friday Apr 12, 2019
Location POB 6.304
Hosted by Thomas O'Leary-Roseberry