Multiple transonic shock-wave/turbulent boundary-layer interaction in a circular duct

An experimental study is described in which detailed pitot, static, and wall pressure measurements have been obtained for multiple transonic shock-wave/turbulent boundary-layer interactions in a circular duct at a freestream Mach number of 1.49, a unit Reynolds number of 4.90xl0/m, and a blockage of 5.15%. The details of the flowfield show the formation of a series of normal shock waves with successively decreasing strength and decreasing distance between the successive shock waves up to the point where a terminal shock occurs. A one-dimensional flow model based on the boundary-layer displacement thickness is postulated to explain the formation of the series of normal shock waves. A comparison with the results from our previous study involving a single shock interaction suggests that the effect of increased blockage is to promote multiple shock interactions and produce a lower pressure recovery, a less retarded boundary-layer flow, and an increase in the overall length of the interaction.