COLLOQUIUM

Monday, October 23, 2006

"A Matrix Free Newton /Krylov Method for Coupling Complex Multi-Physics Subsystems"

Presented By

Dr. Yunlin Xu
Visiting Professor at the Department of Nuclear Engineering
Purdue University

A general approach is proposed for solving coupled nonlinear subsystems using Matrix Free Newton /Krylov (MFNK) methods. A system of nonlinear equations is defined based on a Fixed Point Iteration (FPI) scheme which does not require the reformulation of the coupled subsystems into a larger system of equations. This makes it possible for each of the subsystems to retain their respective solvers for the individual field equations. It is shown that even for the cases in which the corresponding FPI diverges, the MFNK can achieve q-quadratic but at least q-linear local convergence. Analysis of global convergence strategies indicates that Line Searches and Model Trust Region strategies can be implemented efficiently for MFNK.

Coffee and Cookies 3:45 PM - Colloquium 4 - 5 PM
3105 Etcheverry Hall