On the influence of shear layer instability on the bow shock in hypervelocity shock wave interaction

In hypervelocity shock wave interaction pow fields shear layers are observe d separating subsonic from supersonic pour regions. These shear layers beco me unstable if the Reynolds number is large enough. Assuming a convective v elocity of the developing structures, convective Mach numbers can be define d in a frame of reference moving with the structures. Endothermic dissociat ion reaction reduces the speed of sound, thereby the convective Mach number increases. If these convective Mach numbers become transonic or supersonic shock waves emanate from the shear layer into the adjacent flow fields. Th ese shock waves are travelling waves in the laboratory frame, the flow fiel d becomes unsteady.