Characterizing the Mach 6 Flow of Virginia Tech's Hypersonic Wind Tunnel

A recommissioning and characterization campaign is currently underway for Virginia Tech's hypersonic wind tunnel to assess its operational capabilities. The facility operates between Mach 2 and Mach 7, and has been used for basic aerodynamic measurements and advanced instrumentation development. This study focuses on characterizing the tunnel's Mach 6 nozzle's full range of capabilities, including the operational range, core measurement techniques, and the potential for advanced optical diagnostic techniques. Characterization results define the facility's performance metrics and limitations. A new test article mounting system has been constructed and tested to prevent flow blockage. Two measurement techniques, Focused Laser Differential Interferometry and High-Speed Schlieren, have been implemented into the tunnel to investigate its inflow noise and flow quality, respectively. Inflow uniformity and shear layer characteristics were obtained using a traversing Pitot tube system. Focused Laser Differential Interferometry was used to investigate the freestream turbulence of the Mach 6 nozzle by measuring the flow density fluctuations. All results suggest the Mach 6 nozzle of the wind tunnel produces flow with acceptable uniformity and turbulence levels for the types of measurements currently under study. Similar characterization of the Mach 2, 3, 4, 5, and 7 nozzles is ongoing.