ACMD Seminar: Numerical Methods for Studying Particle Dispersion in Non-Homogeneous Suspension Flows

Amanda Howard
PhD Candidate, Division of Applied Mathematics, Brown University

Friday, March 9, 2018, 15:00 - 16:00
Building 101, Lecture Room B
Gaithersburg

Friday, March 9, 2018, 13:00 - 14:00
Room 1-4058
Boulder

Abstract: Suspension flows represent a complex dynamical system due to the nonlinear coupling of the flow and the particle positions, which in turn determine the flow. Even in the zero Reynolds number Stokes flow limit, where the flow is linear and reversible, the presence of particles induces chaos and irreversibility. This talk will discuss two numerical methods to study the sources of irreversibility in a suspension flow: the Force Coupling Method (FCM) and Generalized Moving Least Squares (GMLS). In FCM, the particles are represented by a low-order force-multipole expansion, providing a matrix-free method to solve for the particle motion, which allows for efficient simulations of dense suspensions of spherical particles while resolving short-range lubrication forces of tightly packed particles as well as the long-range hydrodynamic forces. GMLS is a meshless method that uses polynomial interpolants to provide high order solutions using only the graph of neighbor connectivity, allowing handling of non-spherical particles and complex, moving boundaries. Results from these methods for non-homogenous suspensions will be shown to demonstrate the relative importance of the particle surface roughness, lubrication forces, and long-range hydrodynamic forces on the particle dispersion.

Bio: Amanda Howard is a Ph.D. candidate at Brown University in the Division of Applied Mathematics. Her research focuses on scientific computing and numerical methods in computational fluid dynamics, particularly applied to suspension flows of non-Brownian particles, as well as efficient implementation of higher order meshless methods. She is a recipient of a 2014 National Science Foundation Graduate Research Fellowship. 

Note: Visitors from outside NIST must contact Cathy Graham; (301) 975-3800; at least 24 hours in advance.