A NEW FLUX SPLITTING SCHEME

A new flux splitting scheme is proposed. The scheme is remarkably simple and yet its accuracy rivals, and in some cases surpasses, that of Roe's solver in the Euler and Navier-Stokes solutions carried out in this study, The scheme is robust and converges as fast as the Roe splitting. We propose an appropriately defined cell-face advection Mach number using values from the two straddling cells via associated characteristic speeds. This interface Mach number is then used to determine the upwind extrapolation for the convective quantities. Accordingly, the name of the scheme is coined as the advection upstream splitting method (AUSM). We also introduce a new pressure splitting which is shown to behave successfully, yielding much smoother results than other existing pressure splittings. Of particular interest is the supersonic blunt body problem in which the Roe scheme gives anomalous solutions. The AUSM produces correct solutions without difficulty for a wide range of flow conditions as well as grids. © 1993 Academic Press, Inc.