Optimization of multilayer thermal protection system by using phase change material under aerodynamic heating

Abstract

• MTPSs using PCM for insulation are numerically studied. • The addition of PCM helps MTPS fulfill the thermal requirements. • PCM proportion plays a major role in the mass optimization result. • The contents of the two insulation layers affect the system differently. • The optimized designs in terms of mass and size is related to the type of PCM. A multilayer thermal protection system (MTPS) capable to work constantly during multiple launches is important for the new generation of reusable re-entry vehicles to significantly reduce launch costs and protect instruments from overheating. In this paper, phase change material (PCM) is introduced into the MTPS for the optimization purpose in terms of heat performance and structure design. The transient heat transfer characteristics of the system under aerodynamic heating is numerically analyzed, and 2D models using different insulation materials are compared to optimize the system, with respect to temperature distribution, areal density and overall thickness. The finite volume method with the enthalpy-porosity technique is used to resolve the involved multilayer heat transfer problem and the phase transition process. The thermal radiation between the system and the environment, the heat conduction through multi layers, and the convective phenomenon occurring in the PCM section are all considered. The calculation result confirms that the addition of PCM can successfully decrease the temperature of each part in the system below their maximum temperature limits (the C/SiC, Saffil and aluminum alloy layers lower than 1923.15 K, 1873.5 K and 450 K, simultaneously), accordingly help to find the optimal designs with a lighter mass and a smaller size.