A FAST, HIGH-RESOLUTION, 2ND-ORDER CENTRAL SCHEME FOR INCOMPRESSIBLE FLOWS

A high resolution, second-order central difference method for incompre ssible flows is presented, The method is based on a recent second-orde r extension of the classic Lax-Friedrichs scheme introduced for hyperb olic conservation laws (Nessyahu H, & Tadmor E, (1990) J. Comp. Physic s, 87, 408-463; Jiang G,-S, & Tadmor E, (1996) UCLA CAM Report 96-36, SIAM J, Sci, Comput., in press) and augmented by a new discrete Hedge projection, The projection is exact, yet the discrete Laplacian operat or retains a compact stencil, The scheme is fast, easy to implement, a nd readily generalizable. Its performance was tested on the standard p eriodic double shear-layer problem; no spurious vorticity patterns app ear when the flow is underresolved. A short discussion of numerical bo undary conditions is also given, along with a numerical example.