CURVATURE FLOW AND ENTROPY CONDITIONS APPLIED TO GRID GENERATION

We describe a numerical technique to generate logically rectangular bo dy-fitted interior and exterior grids. The technique is based on solvi ng a Hamilton-Jacobi-type equation for a propagating level set functio n, using techniques borrowed from hyperbolic conservation laws. Coordi nate grid lines are kept smooth through curvature terms which regulari ze the equation of motion, and upwind difference schemes which satisfy the correct entropy conditions of front propagation. The resulting al gorithm can be used to generate two- and three-dimensional interior an d exterior grids around reasonably complex bodies which may contain sh arp corners and significant variations in curvature. The technique may also be easily extended to problems of boundary-fitted moving grids. (C) 1994 Academic Press, Inc.