Some possibility of reverse phenomenon for supersonic flows in free jets

Unstable reverse zones in free supersonic jets is discovered numerically using finite-volume flow solver. Reverse zones may observe behind the Mach disk as in first so and second cells of underexpanded jets and in second cell of overexpanded jets. It's determined the region of reverse origin in Mach number-expansion ratio plane by some initial and others conditions. Part of this region is corresponded to supersonic reverse with own shock structure. All testes as well as similar to experiment centerline contrary pressure gradient in reverse sector is confirmed possibility such physical phenomenon.