A Procedure to Evaluate the Thermal Response of a Multilayered Thermal Protection System Subjected to Aerodynamic Heating

Abstract

Next generation reusable re-entry vehicles must be capable of sustaining consistent repeated aero-thermal loads without damage or deterioration. This means that such structures must tolerate the high temperatures engendered by aero-thermal re-entry fluxes due to the establishment of a hypersonic regime over the body. Thermal Protection Systems (TPS) are used to maintain a reusable launch vehicle’s structural temperature within acceptable limits during re-entry flights; that is, internal temperature should not overcome the temperature limit use of the internal structure. TPS are usually composed by several layers made of different materials. Heat transfer through a multilayer insulation during atmospheric re-entry involves combined modes of heat transfer: heat conduction through the solid, heat radiation to the outer space etc. In the frame of TPS design activities a procedure based on one dimensional analytical solutions of transient nonlinear analyses has been developed in order to estimate the temperature variation with time and space of a multilayered body subjected to aerodynamic heating inside a radiating space. Since internal temperature values of TPSs of re-entry vehicles cannot exceed certain values, that procedure allows to quickly evaluate those temperature values and to preliminary size layer thicknesses before preparing and performing Finite Element analyses.