A new generation tailored thermal protection material for hyperonic boundary layer control

Abstract

The current study aims for a new class of porous thermal protection material (TPS) able to withstand the extremely demanding hypersonic flight environment and being applicable for active and passive hypersonic boundary layer control through tailored porosity. The study addresses two of the many challenges to master hypersonic sustained flight; high surface heat fluxes and viscous drag in combination with the need to develop advanced high temperature materials. The study explores different manufacturing techniques to develop a new temperature stable, C/C-SiC material with controllable porosity. The technique will reuse selected components of an existing process to manufacture C/C-SiC, which is a temperature stable and oxidation resistant material used as TPS on hypersonic test vehicles. To generate the porosity a novel approach is chosen by using 3D-reinforcement techniques such as Z-pinning, tufting and stitching. The design of the porous TPS will be guided by a methodology leading to optimal porosity parameters to control surface heat flux and vehicle drag by means of active and passive boundary layer control techniques such as mass injection into the boundary layer and boundary layer transition delay by means of ultrasonic absorption of instabilities. Ultimately, the study aims for verification tests at hypersonic flight conditions in the High Enthalpy Shock Tunnel (HEG) at DLR Göttingen.