Main flight data on transpiration cooled sharp edge fins in hypersonic conditions on the sounding rocket HIFLIER

• A flight experiment for transpiration cooling to sharp-edge fins was carried out. • The fins’ leading edge was made of a porous variant of the C/C-SiC material. • The experiment was performed during the flight of the sounding rocket HIFLIER. • Precious reliable data were collected in real hypersonic flight conditions. • The transpiration cooling had an efficiency up to 40 %. Transpiration cooling is a promising thermal management technique that could be applied in hypersonic regimes to protect critical external structural components subjected to the highest aerothermal pressure and heat loads. In the framework of the HIFLIER program, a module of the sounding rocket scientific payload has been designed and setup to test the application of the transpiration cooling in real hypersonic flight conditions to sharp edge fins, whose leading edge is made of an innovative porous C/C-SiC material, so-called OCTRA. The module was integrated into a single-stage sounding rocket that was successfully launched into a parabolic trajectory reaching hypersonic conditions during ascent and during descent, with a maximum Mach number of 6.15. This paper presents the setup of the experimental system and its integration in the rocket module as well as the main collected flight data. The results validate the transpiration cooling technology, showing a good response of the system with a cooling efficiency of up to 40 % in hypersonic regime in both the ascent and the descent phases.