Experimental Investigation of the Time-Dependent Separation of Tangent Bodies inSupersonic Flow

摘要

An experimental, time-dependent separation of tangent bodies was performed in asupersonic wind tunnel (Mach 1.5 and 1.9) to investigate the significance of transient effects and the suitability of using steady-state assumptions to predict a dynamic even. The model configurations consisted of two bodies placed in a near tangent position. A stationary body, plate or ogive, was instrumented to obtain dynamic surface pressures, while a second body, a wedge attached to an air cylinder, was plunged in a constrained motion away from and towards the stationary model. Three-dimensional flow expansion around the edge of the wedge reduced the strength of the shock waves and created a region of low pressure, near freestream static, on body surfaces between the incident and reflection shock waves. The dynamic motion of the wedge did not significantly affect the shock wave development between the bodies, and steady-state corrections that accounted for the motion-induced wedge angle were appropriate for predicting the time-dependent surface pressures induced by the incident shock wave.