Combination of Preconditioned Krylov Subspace Methods and Multi-grid Method for Convergence Acceleration of the incompressible Navier-Stokes Equations

비압축성 Navier-Stokes 방정식의 수렴 가속을 위한 예조건화 Krylov 부공간법과 다중 격자법의 결합

In this article, combination of the FAS-FMG multi-grid method and the Krylov subspace method was presented in solving two dimensional driven-cavity flows. Three algorithms of the Krylov subspace method, CG, CGSTAB(Bi-CG Stabilized) and GMRES method were tested with MILU preconditioner. As a smoother of the pressure correction equation, the MILU-CG is recommended rather than MILU-GMRES(k) or MILU-CGSTAB, since the MILU-GMRES(k) preconditioner has too much computation on the coarse grid compared to the MILU-CG one. As for the momentum equation, relatively cheap smoother like SIP solver may be sufficient.