Heat Flux Anomaly In High-Enthalpy And High-Reynolds Number Flow

Abstract

The series of aerodynamic heating test campaigns with blunt shaped models in hypersonic high-enthalpy flow were conducted in JAXA-HIEST. Four different blunt shaped models were applied in this study; Apollo CM 6.4% scale model, HRV capsule 6% scaled model and two hemi-sphere probes with radius of curvature r=20mm and r=100mm. Numerical analysis with an axis-symmetric Navier-Stokes thermo-chemical non-equilibrium code was also conducted. Stagnation pressure was almost fixed to P0=50MPa, while stagnation enthalpy was varied from H0=7MJ/kg to 21MJ/kg. The unit Reynolds number under the condition was 0.9million/m to 3million/m and the boundary layer was hence mainly fully laminar flow. Abnormal high-heat flux was observed under high enthalpy condition (H0>10MJ/kg), which anomalies were almost twice higher than those of numerical calculations or theoretical ones. The measurement with four different blunt models showed that the abnormal heat flux was increased as stagnation enthalpy. From the analysis of compression process of the free-piston driver, radiation heating from driver gas does not seem to explain this heating anomaly. The numerical analysis implied that the heating anomaly was related to radiation from unknown atoms or molecules in shock layer . Senior Researcher, Space Transportation Propulsion Research and Development Center, Space transportation mission directorates, tanno.hideyuki@jaxa.jp, Member AIAA Senior Researcher, Space Transportation Propulsion Research and Development Center, Space transportation mission directorates Deputy Manager, Space Transportation Propulsion Research and Development Center, Space transportation mission directorates, Senior member AIAA Graduate student, Department of Aerospace Engineering, ishihara@cfd.mech.tohoku.ac.jp, member AIAA Assistance Professor, Department of Aerospace Engineering, yogi@cfd.mech.tohoku.ac.jp, Member AIAA Professor, Department of Aerospace Engineering, sawada@cfd.mech.tohoku.ac.jp, AIAA Associate Fellow 43rd AIAA Thermophysics Conference 25 28 June 2012, New Orleans, Louisiana AIAA 2012-3104 Copyright © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. American Institute of Aeronautics and Astronautics 2