Symmetric and Asymmetric Performance Investigation of a Diverterless Supersonic Inlet

Abstract

A series of wind-tunnel tests were conducted on a Y-shaped diverterless supersonic inlet (DSI) in order to investigate its performance at various operating conditions. The present DSI was designed for a freestream Mach number of . The experiments were performed at supercritical, critical, and subcritical operating conditions and at 0 deg angle of attack and angle of side slip. The results showed that the present DSI had an acceptable performance at its design condition. A symmetric supersonic flow pattern was observed at both supercritical and critical operating conditions. At low subcritical operating conditions, the supersonic flow pattern remained symmetric too. However, at high subcritical operating conditions, an asymmetric supersonic flow pattern was observed at both 0 deg angle of attack and sideslip angle. Moreover, an asymmetric pressure ratio distribution inside both diffusers, left and right, were observed. This asymmetric flow behavior in a perfectly symmetric Y-shaped DSI inlet seems to have not been noticed by the previous researchers, but if it has, the result has not been published yet. The performance curve of the current DSI presented at both symmetric and asymmetric flow patterns reveal a significant reduction in its performance characteristics at high subcritical operating conditions that is believed to be caused by the asymmetric flow patterns. In addition, symmetric and asymmetric secondary normal shock- wave patterns were further observed during both supercritical and high subcritical operating conditions. It is observed that the flow asymmetry in this inlet happened when the inlet exit area had blocked more than 50% of the aerodynamic interface plane.