A FINITE-DIFFERENCE METHOD FOR 3D FLOWS ABOUT BODIES OF COMPLEX-GEOMETRY IN RECTANGULAR COORDINATE SYSTEMS

A finite difference simulation method is developed for 3D flow about a body of complex geometry. The Navier-Stokes equation is approximated by a high-order-accurate difference scheme in the framework of rectangular co-ordinate systems. The configuration of the 3D body is represented by use of both surface porosity and volume porosity and the no-slip body boundary conditions are approximately implemented on the boundary cells. The validity of the method is demonstrated by a numerical test of flow past a sphere at a Reynolds number of 1000. The complicated structure of separated vortices is well revealed by this test computation. The versatility of the method is shown by application to an ocean-engineering problem of flow about a bay with an island.