A Fully-coupled Newton-Krylov Solution Method for Parallel Unstructured Finite Element Fluid Flow, Heat and Mass Transfer Simulations

摘要

This manuscript briefly describes a robust iterative solution methodology used for parallel unstructured finite element simulation of strongly coupled fluid flow, heat and mass transfer. The solution method relies on an inexact Newton scheme and linear system solvers based on preconditioned Krylov subspace methods. The discussion considers computational efficiency and robustness issues related to the proposed schemes. The evaluated preconditioning techniques include simple polynomial expansion and multi-step block iterative methods along with overlapping Schwarz domain decomposition techniques using subdomain solvers based on incomplete factorizations. For this comparison a particular spatial discretization of the governing transport PDEs based on a Galerkin Least Squares (GLS) finite element formulation is used. Results are presented for some standard 2D CFD benchmark problems as well as for a number of 3D problems.