A novel mechanical-thermal-electrical thermal protection system concept and its multi-scale performance evaluation for hypersonic launch vehicles

In this paper, a multifunctional thermal protection system (MTPS) concept with additional functions of thermoelectric (TE) conversion and load bearing is developed for a hypersonic launch vehicle. The concept is a plate in macroscale and a unit in mesoscale. The mesoscopic unit consists of a TE module and a TPS gap. The TE module consists of an alumina ceramic layer and a fiber insulation layer to dissipate certain amount of the aerodynamic heat, a high-temperature and a mid-temperature TE layers to efficiently convert aerodynamic heat into electric energy, a load-bearing frame and honeycomb cores to improve the load bearing capacity, embedded electricity conducting plates in TE materials and low-modulus high-temperature adhesives to alleviate the thermal stress. The mechanical-thermal-electrical performance of the MTPS is evaluated based on the multi-scale analysis of the flight vehicle, MTPS plate and MTPS unit, and the transfer method of mechanical boundary conditions between different scales is developed. The results show that the multi-scale analysis is essential to ensure the accuracy of boundary conditions, and the developed MTPS concept has multi effective functions of load bearing, heat protection and power supply.