A Numerical Study of the Limiting Cases of Cylinder-Induced Shock Wave/Boundary Layer Interactions

One of the limiting factors in the design of supersonic and hypersonic vehicles remains the prediction and control of the high aerodynamic, thermodynamic, acoustic, and structural loads generated by a shock wave/boundary layer interaction (SWBLI or SBLI). In conjunction with an experimental campaign produced within the research group, a numerical study was performed using a semi-infinite cylinder to generate a SWBLI at Mach 1.88 with both laminar and turbulent boundary layers. The goals were not only to better understand the complex flow surrounding the cylinder-induced turbulent interaction, but also to establish the interaction bounds of the limiting cases of a transitional interaction.

Steady-state Reynolds-averaged Navier-Stokes (RANS) simulations were performed to predict the shock structures, separation and attachment points, and pressure profiles in the upstream region and on the cylinder leading edge. A variety of turbulence models were tested, namely the cubic k-epsilon (CKE), Menter’s shear-stress transport (SST), and Spalart-Allmaras (SA) with quadratic constitutive relations (QCR). Both the CKE and SA-QCR turbulence models showed good agreement with in-house experimental data and literature, and are thus recommended for future use in these types of flow fields. Correlations between the vortex structures and peak and trough pressures were found, thus allowing for a steady-state flow characterization. The effect of varying the incoming boundary layer height was studied, when all other values were kept constant, and it was determined that an increased boundary layer height decreased both the interaction scale and the peak pressure.