Xiangfa Zhou

By Xiangfa Zhou

Thermal control systems and heat insulation materials are required for a range of hypersonic vehicles ranging from ballistic reentry to hypersonic cruise vehicles, both within Earth’s atmosphere and non-Earth atmospheres. The combined thermodynamic/heat transfer relations of the phase change materials (PCMs) in silica nanoporous materials are developed to obtain mass, thickness, and temperature excursion as functions of percentage area of PCM under given maximum energy and thermal flux. The studies show that PCMs are one of the most preferred methods to thermal control applications that can effectively delay or modify the temperature rise of the surface of the aircrafts subjected to high thermal flux. This chapter also introduces the preparations of porous ceramic matrix phase change composite, putting PCMs to use in the internal thermal control materials for the hypersonic vehicles. Porous ceramic matrix serves as the supporting material, which provides structural strength and prevents the leakage of melted PCMs, and PCMs act as thermal absorb material limiting the temperature abruptly rising of the aircrafts. The structural pore properties of the silica matrix with different molar ratios of ethanol (EtOH)/tetraethoxysilane (TEOS) are investigated to determine suitable porous matrices for PCM. To adjust the pore structure of porous silica matrices with different molar ratios of EtOH and TEOS for PCM infiltration is mainly discussed. Furthermore, numerical and experimental studies are proposed to predict and investigate the thermal absorption characteristics of porous silica infiltrated with PCM for thermal control applications.

Part of the book: Advances in Some Hypersonic Vehicles Technologies