Shockwave boundary layer interaction of laminar/transitional flow past a sharp fin

Abstract

Ever since NASA’s X-plane program had developed demonstrators (X-15) pushing into the hypersonic high altitude flight regimes, the effects of shock impingement and interference on local aerodynamic heating have been a key issue for the design of hypersonic flight concepts. Currently DLR is involved in several flight experiments, one of which is STORT which focuses on aerothermal loads on hot structures. One essential structure flown on the STORT flight experiment is the fins experiment on the third stage. The fins were investigated both on the vehicle, in windtunnels in Cologne and Göttingen but also numerically. For the windtunnel experiment in the HEG (High Enthalpy Shock Tunnel Göttingen) the object of investigation is a plate mounted fin which scales 1:2 to the flight hardware. The fin-induced shock boundary layer interaction (SWBLI) on the plate leads to increased thermal loads. The heat flux on the flat plate and fin are investigated using temperature sensitive paints (TSP). For the current study the flow on the plate and around the fin is studied for two HEG freestream conditions at Mach 7.4 using RANS CFD. CFD calculations at both 0 deg AoF and 15 deg AoF were performed and compared for flow topology and turbulence model influence. For 2 configurations first preliminary comparisons between experimental and CFD data were conducted. While the XIII freestream condition compares well between experiment and CFD, the XV freestream condition which shows clear signs of transitional flow exhibits rather complex physical phenomena which requirevfurther investigation, both experimentally and numerically.