Multigrid Application!lll A New Coupled Elliptic Solver: A Preliminary Study

ABSTRACT..A new multigrid scheme using halfsweep four-point explicit.decoupled group (EDG) method in solving the steady-state incompressible Navier-Stokes equation is presented. The concept of hallsweep multigrid was initiated by Othman and Abdullah (J997) where promising results was established and confirmed. In this paper. we apply the multigrid V.cycfe algorithm on the four point explicit decoupled group (EDG). In A Ii and Abdullah [5]. a new group iterative scheme. the Explicit Decoupled Group scheme, was developed as a more efficient Navier-Stokes solver on rotated grids compared to the iterative schemes based on the standardfi.ve-pointformulae and the Alternaiing Group Explicit scheme due to Sahimi and Evans {10J. Our aim in this work is to investigate the possibility ofcombining multigrid technique with this second order group iterative scheme to solve the steady-state incompressible Navier-Stokes equation as a way to further improve the convergence ofthe method, The mu/tign'dformula will be constructed to accelerate the convergence ofthe iterative process for large Reynolds numbers previously claimed not possible for the original iterative scheme. The preliminary study ofthe experimental work performed will be reported. 1. INTRODUCTION. Conside