||September 28, 2012 14:21
MUSCL shock capturing on high aspect ratio meshes
I have noticed that MUSCL generates oscillations (non-monotone behavior) behind oblique shocks if the mesh aspect ratio is high. The problem does not seem to occur near walls where structured meshes have very high aspect ratios. There are situations like backward facing step problem where downstream of the corner, mesh is highly anisotropic. If the shock is at an angle of 45 degrees and aspect ratio is 10, then shock will be 2-3 points wide in one direction and 20-30 points in the other. When the limiter tries to sharpen the shock front in latter direction, one ends with a stair case shaped shock and post shock oscillations. Any thoughts on this other than the simple suggestion of avoiding high anisotropy will be greatly appreciated.