Investigation of an Inward Turning Intake in a Mach 6 Quiet Tunnel at Off-Design Conditions

View Video Presentation: https://doi.org/10.2514/6.2023-3897.vid A high-speed, shape-transitioned waverider inlet, with a total contraction ratio of 5.16:1, is tested within the Purdue Mach 6 Quiet Tunnel. The wind tunnel model, called the Indiana Inlet, is designed for investigation of flow phenomena that occur within high performing inward-turning inlets. The inlet model is tested under conventional freestream noise levels and compared with previously completed quiet flow tests. The inlet boundary layer is shown to transition early due to the influence of freestream noise. Additional statistical anlaysis is carried out to determine the location of transition onset on the inlet forebody. Power spectra of select pressure transducers detect high-frequency pressure signals indicative of different boundary layer instabilities. These instabilities grow at different rates depending on freestream Reynolds number and the amount of noise present in the freestream flow. The existence and growth of one of these instabilities causes early transition and breakdown of the laminar boundary layer under noisy flow.