Shack-Hartmann Wavefront Measurements of Supersonic Turbulent Boundary Layers in the TGF

Abstract

Aero-optical environment of the supersonic flow in Trisonic Gasdynamic Facility (TGF) wind tunnel at Wright-Patterson AFB was experimentally measured using a high-speed wavefront sensor. Temporally- and spatially-resolved wavefronts were collected at a range of Mach numbers between 1.5 and 3.0 and the range of Reynolds numbers between 1 and 4 million per foot. Several data reduction techniques, including multi-point spectral crosscorrelation method, were introduced to analyze results and important statistical information about the turbulent boundary layer was extracted and discussed. A novel method was presented for using the frozen flow assumption to recover time-resolved wavefront measurements from spatially resolved 2-D wavefronts that are under-sampled in time. The criteria for using this technique were discussed in detail.