EFFECTS OF IMPLICIT PRECONDITIONERS ON SOLUTION ACCELERATION SCHEMES IN CFD

✍ Scribed by J. O. HAGER; K. D. LEE

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 688 KB
• Volume: 22
• Category: Article
• ISSN: 0271-2091
• DOI: 10.1002/(sici)1097-0363(19960530)22:10<1023::aid-fld392>3.0.co;2-s

✦ Synopsis

Several solution acceleration techniques, used to obtain steady state CFD solutions as quickly as possible, are applied to an implicit, upwind Euler solver to evaluate their effectiveness. The implicit system is solved using either AD1 or ILU and the solution acceleration techniques evaluated are quasi-Newton iteration, Jacobian freezing, multigrid and GMRES. ILU is a better preconditioner than AD1 because it can use larger time steps. Adding GMRES does not always improve the convergence. However, GMRES preconditioned w i t h ILU and multigrid can take advantage of Jacobian fieezing to produce an efficient scheme that is relatively independent of grid size and grid quality.