Petascale Direct Numerical Simulation of Blood Flow

Colloq: Speaker: 
Dr. George Biros
Colloq: Speaker Institution: 
Georgia Tech
Colloq: Date and Time: 
Thu, 2011-01-20 10:00
Colloq: Location: 
Building 5100, Room 128
Colloq: Host: 
Jeffrey Vetter
Colloq: Host Email: 
vetter@ornl.gov
Colloq: Abstract: 
I will present a fast, petaflop-scalable algorithm for Stokesian particulate flows. The goal is the direct simulation of blood, which we model as a mixture of a Stokesian fluid (plasma) and red blood cells (RBCs). Directly simulating blood is a challenging multiscale, multiphysics problem. In terms of the number of cells, we improve the state-of-the art by several orders of magnitude: the previous largest simulation, at the same physical fidelity as ours, resolved the flow of O(1,000-10,000) RBCs. Our new approach has three distinctcharacteristics: (1) we faithfully represent the physics of RBCs by using nonlinear solid mechanics to capture the deformations of each cell; (2) we accurately resolve the long-range, N-body, hydrodynamic interactions between RBCs (which are caused by the surrounding plasma) using the Fast Multipole Method; and (3) we allow for the highly non-uniform distribution of RBCs in space. I will report simulations with up to 260 million deformable RBCs on Jaguar for a sustained 0.7 Petaflops/sec. The largest simulation amounts to 90 billion unknowns in space. I will also report our experience with porting this code to hybrid architectures and discuss scalability results on Keeneland.
Colloq: Speaker Bio: 
George Biros holds Associate Professor appointments with the Schools of Computational Science and Engineering at Georgia Tech and The Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. Prior to joining Georgia Tech, he was an assistant professor in Mechanical Engineering and Applied Mechanics, Bioengineering and Computer and Information Science at the University of Pennsylvania. He received his BS in Mechanical Engineering from Aristotle University 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 from 2000 to 2003.