Setup of flight experiment of transpiration cooled sharp edge fins on the sounding rocket HIFLIER1

Abstract

The flight in hypersonic conditions implies important challenges for the vehicle development concerning the thermal protection of the external structures, especially in the case of sharp leading edges, where the short standoff distance of the forming shock waves typically determines severe aero-thermal loads. In the framework of the HIFLIER1 flight research experiment, the DLR Institute of Structures and Design, in collaboration with the High Enthalpy Flow Diagnostics Group at the University of Stuttgart, is responsible for setting up the so-called FinExII module of the sounding rocket, for flight testing of the transpiration cooling technology applied to porous ceramic matrix composite structures as a possible approach for thermal management of sharp leading edges in hypersonic regime. For this purpose, the module will house four fins, whose leading edge is made of an inhouse-developed porous C/C-SiC material, connected to a gas system feeding nitrogen for the transpiration cooling application. The present paper gives an overview of the module design, supported by efficient numerical modelling to estimate the effect of the transpiration cooling, and the pre-flight activities, including the fins manufacturing and pre-flight characterization as well as the rocket module setup.