Transition of subsonic and transonic expansion-corner flows

A naturally developed turbulent boundary layer past convex corners was studied. Attention is on the transition of subsonic and transonic expansion flows. Convex-corner angle α ranges from 5 to 20 deg, and freestream Mach numbers M_∞ are 0.33, 0.64, and 0.83. Reynolds numbers based on the incoming boundary-layer thickness Re_δ0 are 10.0, 14.9, and 16.8 × 10⁴, respectively. Transition of subsonic and transonic expansion-corner flow is observed at M_∞² α = 6.14. The sudden expansion near the corner is also scaled with this parameter at M_∞ = 0.64 and 0.83, but not for M_∞ = 0.33.