SYMMETRY TECHNIQUES FOR THE NUMERICAL-SOLUTION OF THE 2D EULER EQUATIONS AT IMPERMEABLE BOUNDARIES

The implementation of boundary conditions at rigid, fixed wall boundar ies in inviscid Euler solutions by upwind, finite volume methods is co nsidered. Some current methods are reviewed. Two new boundary conditio n procedures, denoted as the symmetry technique and the curvature-corr ected symmetry technique are then presented. Their behaviour in relati on to the problem of the subsonic flow about blunt and slender ellipti c bodies is analysed. The subsonic flow inside the Stanitz elbow is th en computed. The symmetry technique is proven to be as accurate as one of the current methods, second-order pressure extrapolation technique . Finally, for arbitrary curved geometries, dramatic advantages of the corrected-corrected symmetry technique over the other methods are sho wn. (C) 1998 John Wiley & Sons, Ltd.