Influence of leading edge bluntness on hypersonic flow in a generic internal-compression inlet

Central Aerohydrodynamic Institute (TsAGI) 1 Zhukovsky Str., Zhukovsky, Moscow Region 140180, Russia

Abstract

Flow and heat transfer inside a generic inlet are investigated experimentally. The cross section of the inlet is rectangular. The inlet is installed on a flat plat at a significant distance from the leading edge. The experiments are performed in TsAGI wind tunnel UT-1M working in the Ludwieg tube mode at Mach number M_∞ = 5 and Reynolds numbers (based on the plate length L = 320 mm) Re_∞L = 23 · 10⁶ and 13 · 10⁶. Steady flow duration is 40 ms. Optical panoramic methods are used for investigation of flow outside and inside the inlet as well. For this purpose, the cowl and one of two compressing wedges are made of a transparent material. Heat flux distribution is measured by thin luminescent Temperature Sensitive Paint (TSP). Surface flow and shear stress visualization is performed by viscous oil containing luminophor particles. The investigation shows that at high contraction ratio of the inlet, an increase of plate or cowl bluntness to some critical value leads to sudden change of the flow structure.