Influence of Favorable Pressure Gradients on a Mach 5.0 Turbulent Boundary Layer

Abstract

A series of experiments were conducted to study the effects of favorable pressure gradients on high supersonic (M = 5.0), high Reynolds number (Reθ = 36,000) turbulent boundary layers. Rayleigh scattering was used to visualize the flow-field in combination with planar particle image velocimetry to obtain a quantitative description. The results herein are considered preliminary as we were unable to reduce all of the acquired samples in time for this paper. In summary, time-averaged velocities, fluctuating velocities, and Reynolds stresses were calculated from a subset of acquired data. These data showed the expected stabilizing trends. Comparison to the Mach 3.0, Reθ = 40,000 study of Ekoto et al. on the same models indicated that the axial fluctuations were unaltered by the increase in Mach number. However, the transverse fluctuations and Reynolds shear stresses showed systematic differences.