Hypersonic flow over concave surfaces with leading-edge bluntness

Both Cheng's theory and its modified version using tangent wedge rule are studied for power-law concave surface flows with leading-edge bluntness. It is shown that Cheng's theory yields highly oscillatory results for concave surfaces with blunt leading edge. The tangent wedge analysis is found to predict a smooth transition from the leading-edge blast wave effect to the downstream asymptotic conditions. The alternative use of the tangent wedge formula cannot be justified strictly from theoretical considerations, since it neglects the centrifugal pressure rise on the surface. The good agreement with experimental results obtained for concave surfaces with sharp leading edge using the tangent wedge formula suggests that the analysis presented may be useful in making first estimates, since the effects of the nose bluntness and the boundary-layer displacement are13; similar.13