Investigation on transonic round convex-corner flows

Experiments were performed to investigate the flow of a transonic, turbulent boundary layer over regions of sharp and rounded convex surface curvature. The freestream Mach numbers were 0.64, 0.70, 0.83 and 0.89. Test models with three different radii of curvature from 13.7 to 41.7 times the upstream boundary-layer thickness were employed. The total turning angles were 13, 15 and 17 degrees. The flow was found to be accelerated upstream of the curved region. The peak Mach number decreased with increasing radius of curvature for a given turning angle. In comparison with the sharp convex corner, a delay in the transition from subsonic to transonic expansion flows was observed. The shock structure, boundary-layer separation and peak fluctuating pressure were dependent on freestream Mach number, turning angle and radius of curvature. (C) 2014 Elsevier Masson SAS. All rights reserved.