A preconditioner freeze strategy for numerical solution of compressible flows

摘要

It is well known that Krylov-Schwarz methods are well suited for solving linear Systems of equations in high-latency, distributed memory environments and constitute powerful tools when combined with Newton-Krylov methods to solve Computational Fluid Dynamics problems. Nevertheless, the computational costs related to the Jacobian and the preconditioner evaluation can sometimes be prohibitive. In this work a strategy to reduce these costs is presented, based on evaluating a new preconditioner only after it had been frozen for several time steps. Numerical experiments show the computational gain achieved with the proposed strategy.