Analysis of viscous-inviscid interaction in transonic internal flows

A method is presented to compute steady transonic flows in two-dimensional and annular diffusers, including the effects of shock/turbulent boundary-layer interaction and mass transfer through permeable walls. The analysis is based on the technique of matched asymptotic expansions and results in a system of coupled equations that describes the inyiscid and turbulent boundary-layer flows. The derivation allows for the possibility of shock-induced separation in case of sufficiently strong shocks, assuming the separation bubble size is comparable to the boundary-layer thickness. The numerical procedure required to solve the system of equations is simple, and the computation times are sufficiently short to be useful in engineering design. Results are illustrated for two-dimensional and axisymmetric cases, the former showing good agreement with available experimental data.