The geometry shown here is a version of "Ni's Bump" (it is in fact the same version used in the transonic example). The upper and lower edges of the grid represent solid walls, one of which has a distinct "bump" in it. A subsonic flow is going from left to right across the bump and, in steady state, the flow basically becomes symmetric across the bump. If you use to mach inlet slider to raise the mach number past about 0.7, the flow will become transonic and a shock will develop above the bump. This shows the highly non-linear nature of the problem. A small change in mach number can result in huge changes in the nature of the flow.
Last modified: June 1996
David Oh / Computational Aerospace Sciences Laboratory, MIT / bamf@attbi.com