Numerical Investigation of Mach 2.5 Axisymmetric Turbulent Shock Wave Boundary Layer Interactions

Shock wave boundary layer interactions are common to both supersonic and hypersonic inlet flows. Wall-resolved implicit large-eddy simulations of a canonical Mach 2.5 axisymmetric shock wave boundary layer interaction experiment at Glenn Research Center were carried out. A conical shock wave was generated with axisymmetric centerbodies with 16 deg half-angle cone. The centerbody radii were 9.2% and 14.7% of the test section diameter. The conical shock wave interacted with the turbulent boundary layer on the inside of the cylindrical test section. The experimental Reynolds number based on diameter was six million. For the simulations, the Reynolds number was reduced by a factor of 10 to lower the computational expense. The turbulent boundary layer separates for both centerbody radii and the separation is stronger for the larger centerbody radius. Frequency spectra of the spanwise-averaged wall-pressure coefficient reveal low-frequency content at Strouhal numbers based on separation length between 0.02 and 0.05 in the vicinity of the separation shock and mid-frequency content between 0.1 and 0.2 downstream of separation. A proper orthogonal decomposition captures spanwise coherent structures with a Strouhal number of 0.03-0.04 over the interaction region and streamwise coherent structures inside and downstream of the interaction with a Strouhal number of 0.1-0.4.

Automated summary

Wall-resolved implicit large-eddy simulations were performed to study the shock wave boundary layer interactions on a cylindrical test section with different centerbody radii. The results show that the separation of the boundary layer is more significant for larger centerbody radius. Frequency spectra analysis reveals the presence of low-frequency and mid-frequency features near the separation shock and downstream of separation. Proper orthogonal decomposition analysis captures spanwise and streamwise coherent structures in the interaction region.