Numerical Investigation of Compressible Turbulent Boundary Layer Over Expansion Corner

Abstract

This paper presents an ongoing project on numerical investigation of the rapid distortion and the subsequent relaxation of compressible turbulent boundary layers over expansion corners. A well-validated finite volume flow solver comprising several turbulence models was used to simulate two test cases of supersonic flows encountering abrupt expansions in the mean streamwise direction. When comparing with experiments, it is concluded that commonly used turbulence models are capable of predicting the mean flow quantities and the streamwise normal Reynolds stress downstream of the expansion corner with sufficient accuracies. Numerical analysis found that bulk dilatation (change of mean density) and isovolumetric deformation of normal strain rates are mainly responsible for the turbulence reduction across the expansion fan.