Ground Test and Computation of Boundary Layer Transition on the Hypersonic International Flight Research and Experimentation (HIFiRE)-5 Vehicle.

摘要

The HIFiRE Flight 5 payload was assessed in the NASA LaRC 20-Inch Mach 6 Air Tunnel. The primary objectives were to determine the boundary layer transition characteristics and the effectiveness trips. Boundary layer profiles were extracted from Navier-Stokes calculations of the flow field, and were used to assess trip heights in terms of typical trip correlating parameters. Leading- edge roughness was well-correlated with the R-bar-star parameter. This correlation was used to extrapolate wind tunnel data to full-scale flight conditions. Boundary layer transition was also studied using Parabolized Stability Equation (PSE) analysis. The stability analysis was conducted on the two symmetry planes of the vehicle. The leading edge planes are expected to follow second mode instability growth. The centerline cases experienced a more complicated growth that was mainly driven by second mode, but also showed higher modes. In particular for the lowest altitude case, the higher modes showed to contribute to the maximum N factor growth. This was caused by the complex boundary layer profile that was induced by a pair of vortices along the centerline of the vehicle.