Study on the mechanism of the buzz flow in a supersonic intake

The flow field in a supersonic intake has been investigated computationally to understand the unsteady shock motions at an incoming Mach number of 1.95. The exit area variation is achieved by moving the flap downstream of the inlet model. Inviscid, unsteady simulations of the shock movement are compared with simulations of the viscous flow. The purpose is to understand the possibility of an inviscid mechanism as the underlying process of shock swallowing. It is observed for inviscid simulations that during the shock movement process, the system breaks the steady flow and a transient flow is initiated followed by a new steady state condition. On the contrary, this is not observed in viscous flow simulations which suggest the possibility of an unsteady mechanism that can propagate upstream of supersonic flow to make changes in the flow field. The analysis suggests that shock swallowing is related to the inviscid phenomenon and it may be associated with an unsteady chocking wave.