High Enthalpy Effects on Hypersonic Boundary Layer Transition

Kurzfassung

In the present paper, several boundary-layer stability codes are compared, based on hypersonic, high-enthalpy boundary-layer flows around two different blunted cones: a 7° and a 10.9° half-angle blunted cone. One part of the code-to-code comparison, which is conducted between seven different codes, assesses the influence of different numerical approaches for the second-mode instability. The focus of the paper characterizes the role of the real-gas effects on the second mode. The experimental test cases for the comparison are provided by two high-enthalpy wind tunnel facilities: the High Enthalpy Shock Tunnel (HIEST) of Japan Aerospace Exploration Agency (JAXA) and the High-Enthalpy Laboratory Munich (HELM) of the University of Bundeswehr Munich (UniBwM). Analyses between the various computational stability codes and experimental measurements are performed, as well as quantifying the realgas effects, the influence of uncertainties (e.g., small mean-flow or wall-temperature variations), and the comparison between air and N2 test gases.