DNS and Experimental Study of Shock Wave/Turbulent Boundary Layer Interaction Over a Mach 6.32 Hollow-Cylinder/Flare

This study presents a combined direct numerical simulation (DNS) and experimental investigation of shock wave/turbulent boundary layer interaction (SBLI) over a hollow-cylinder/flare (HCF) configuration at Mach 6.32, with a flare angle of $34^\circ$. The DNS replicates conditions from the Stevens Shock Tunnel, with matched freestream and wall temperature conditions ($Re^u_\infty/m= 13.86\times 10^6$, $T_w/T_r = 0.54$). Detailed comparisons of DNS against experiments are made. Upstream of the interaction, the simulation shows excellent agreement in mean velocity profiles and Morkovin-scaled turbulence intensities with Stevens' experiment, as well as with other flat-plate data in the literature. Within the flare-induced SBLI region, the DNS captures key features of separation, reattachment, and shock-induced surface loading. Instantaneous schlieren images from the DNS closely match the experimental schlieren, capturing the structure and dynamics of shock motion and the evolving separation bubble. Additionally, wall pressure signals from the DNS align well with Kulite measurements, with improved agreement observed after applying low-pass filtering to account for sensor's effective bandwidth.