ALTERNATE FORMULATIONS FOR THE PRESSURE EQUATION LAPLACIAN ON A COLLOCATED GRID FOR SOLVING THE UNSTEADY INCOMPRESSIBLE NAVIER-STOKES EQUATIONS

The solution of the unsteady incompressible Navier-Stokes on a colloca ted grid is investigated. A consistent formulation to construct the La placian in the pressure equation is developed. It is shown that within this framework, Laplacians with different characteristics can be cons tructed, which can be made to satisfy discrete continuity and consider ably reduce pressure oscillations. A third-order forward-biased approx imation for the gradient operator of pressure works very well in compl etely eliminating pressure oscillations in a lid-driven cavity flow te st problem. (C) 1995 Academic Press, Inc.