NUMERICAL ISSUES AFFECTING VORTEX ASYMMETRIES COMPUTED WITH THE CONICAL NAVIER-STOKES EQUATIONS

An implicit upwind symmetric factorization finite volume solver for th e conical Navier-Stokes equations was used to compute asymmetric vorti ces about a 5 degrees cone at a 20 degrees angle of attack. Asymmetric vortices were computed with no asymmetric disturbances other than com putational roundoff errors. Variations in grid resolution, flux limite rs and grid symmetry were studied. A brief proof of algorithm symmetry is included as an appendix. The results indicate that numerical dissi pation in the form of flux limiters or poor grid resolution can preven t the formation of asymmetric vortices in a manner similar to that sho wn by Thomas [15] [J. Thomas, Reynolds number effects on supersonic as ymmetrical flows over a cone. J. Aircraft 30, 4 (1993)] for viscous di ssipation. (C) 1996 Elsevier Science Ltd.