The distortion of a supersonic turbulent boundary layer by bulk compression and surface curvature

An experimental investigation of a supersonic turbulent boundary layer experiencing the effects of bulk compression and streamline curvature is described. The incoming boundary layer l.ad a Mach number of 2.87 and a unit Reynolds number of 6.3 × 10⁷/m. Two different, constant-radius curved-wall models were used, one with δ_D/R = 0.10 (Model I) and one with δ_O/E = 0.02 (Model II). The total turning angle for botL cases was fixed at 8°. Dramatic increases in the turbulent normal and shear stresses were observed. The amplification of the normal stress was about the same in both models whereas the amplification of the shear stress was greater in Model I compared with Model II. The turbulence behavior for Model I was similar to that observed in the corresponding 8° compression corner flow, and the flow in the compression corner arid in Model I can be classed as “rapid” perturbations, in that the turbulence behavior appears to depend only on the total strain applied. The flow over Model II cannot be so easily classified and appears to be considerably more complex.