Note on the Assessment of Flow Disturbances at a Blunt Body Traveling at Supersonic Speeds Owing to Flow Disturbances in Free Stream

Abstract

For the purposes of assessing the magnitude of flow disturbances which would affect conditions on a blunt nose of a body moving at supersonic speeds, the detached shock is approximated by a purely normal shock. The disturbances downstream of the shock are expressed in terms of the “free-stream” disturbances by considering sinusoidal fluctuations. Pressure fluctuations generated by interactions of entropy-temperature disturbances with the normal shock may be considerable at high Mach numbers, but their effect on the transition of a laminar boundary layer to a turbulent one is a matter of speculation. However, conjectures that reflections of such pressure waves between the body and the shock wave might lead to high resonant amplifications are definitely disproved.