Experimental Investigation of a Hypersonic Inlet with and Without Sidewall Compression

摘要

The inlet of a Mach 8 cruise vehicle has been experimentally investigated in a hypersonic blowdown wind tunnel with test times of up to 30 s. Two test series have been carried out: the first one with a two-dimensional inlet configuration and the second one with the inlet featuring additional sidewall compression. The objective of the tests was to determine the performance of the inlet at ondesign and offdesign conditions, i.e., at angle of attack and angle of yaw. Additionally, the starting behavior of the inlet has been determined, i.e., the contraction ratio at which the inlet starts. Results were interpreted from schlieren visualizations, infrared thermograph}, static and pitot pressure readings, and mass flow measurements. The offdesign investigation of both inlet configurations revealed the sensitivity of the inlet toward a cowl-shock-induced separation on the second compression ramp. If the cowl shock was not ensured to fall into the bleed duct behind the second ramp, no inlet flow could be established. The comparison of starting contraction ratios showed the advantage of the inlet with sidewall compression; that is, the inlet with sidewall compression starts at higher contraction ratios.