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AMCS Colloquium

Friday, December 13, 2019 - 2:00pm

George Biros

Oden Institute / University of Texas at Austin

Location

University of Pennsylvania

A6 DRL

ABSTRACT:

I will discuss fast solvers, reduced order models, and optimization methods for fluid-structure interaction problems in the zero Reynolds number regime.  Our goal is to design a deterministic lateral displacement (DLD) device to sort same-size biological cells by their deformability, in particular to sort red blood cells (RBCs) by their viscosity contrast between the fluid in the interior and the exterior of the cells.  A DLD device optimized for efficient cell sorting enables rapid medical diagnoses of several diseases such as malaria since infected cells are stiffer than their healthy counterparts.  In this context, I will first describe an integral equation formulation that delivers optimal complexity solvers for this type of problems.  Despite its excellent theoretical properties, our integral equation solver remains prohibitively expensive for optimization and uncertainty quantification.  I will then summarize our efforts to reduce the computational costs, starting from low-resolution discretization, domain truncation, and model reduction.  Model reduction is used to accelerate the action of specific and very expensive nonlinear operators.  The final scheme blends ultra low-resolution solvers (who on their own cannot resolve the flow), several regression neural networks, and an operator time-stepping scheme, which we introduced to specifically enable the use of surrogate models.  We have used our methodology successfully for flows that are completely different from the flows in the training dataset.  I will present results that demonstrate the capabilities of the methodology.
 
This is joint work with Gokberk Kabacaoglu.

BIO:

George Biros is the W. A. "Tex" Moncrief Chair in Simulation-Based Engineering Sciences in the Institute for Computational Engineering and Sciences and has Full Professor appointments with the departments of Mechanical Engineering and Computer Science (by courtesy) at the University of Texas at Austin.  From 2008 to 2011, he was an Associate Professor in the School of Computational Science and Engineering at Georgia Tech and The Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.  From 2003 to 2008, he was an Assistant professor in Mechanical Engineering and Applied Mechanics at the University of Pennsylvania.  He received his BS in Mechanical Engineering from Aristotle University in Greece (1995), his MS in Biomedical Engineering from Carnegie Mellon (1996), and his PhD in Computational Science and Engineering also from Carnegie Mellon (2000).  He was a postdoctoral associate at the Courant Institute of Mathematical Sciences from 2000 to 2003.  Biros was among a team of researchers that won the IEEE/ACM SC03 and SC10 Gordon Bell Awards.