For more information about this meeting, contact Victor Nistor, Stephanie Zerby, Mark Levi, Jinchao Xu, Ludmil Zikatanov.
|Title:||Block Preconditioning for Multi-physics: From Jacobi to Schur Complements*|
|Seminar:||CCMA Luncheon Seminar|
|Speaker:||Eric Cyr, Sandia Natl. Lab.|
|Developing scalable solvers for fully-coupled multi-physics is challenging. One approach is to use advanced multigrid algorithms to achieve scalability on these problems. However, this approach can suffer from stability issues, in particular the coarse grid operators used in AMG can become ill-conditioned. An alternative to fully-coupled multigrid is to use a block decomposition of the linear system. This segregates the linear system into physical fields, for instance separating Navier-Stokes into velocity and pressure components leads to a 2x2 Jacobian operator. These approaches are appealing because segregated operators are more amenable to multigrid, yet achieving good parallel scalability for the coupled system is still possible. The difficulty with these methods is efficiently and effectively handling the coupling between the different physics. In this talk I will overview a number of block preconditioners focusing on exploiting the structure of the operators. Furthermore, I will present a few techniques for approximating Schur-complement operators. To make this concrete, applications in fluid dynamics and magnetohydrodynamics will be discussed.
*This work was partially supported by the DOE office of Science Applied Math Program at Sandia National Laboratory. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DEM-AC04-94AL85000.|
Room Reservation Information
|Date:||11 / 02 / 2012|
|Time:||12:20pm - 01:30pm|