航天飞行器热防护系统的一体化设计

航天飞行器进入大气层时经受强烈的气动加热,需借助于热防护系统以保护其免受气动热的伤害;飞行器机翼前缘和鼻罩是最高温区,该处的温差相当大,热防护措施尤其重要。作为热防护系统一方面要抵抗强热的冲击,另一方面要最大限度地减少气动热传入结构的内壁,这就对防热系统所用材料提出不同的要求。抗热冲击要求材料质密而隔热但又要求质轻,这就是矛盾所在。随着复合材料的发展,这对矛盾可以通过利用不同材料特性把防热系统分层来解决,从而导致一体化设计的概念和方法。本文利用热传导理论对两层结构的防热系统进行一体化设计分析。

Integrated Design of Spacecraft Heat Protection System

A spacecraft at reentry into atmosphere would undergo severe aerodynamic heating, hence some kind of thermal protection system must be provided to some parts of the structure, especially on its front nose and leading edge of the wing. These protection systems must with- stand the heat impact and at the same time retard the heat transmission into the understructure. But, these requirements are contradictory for materials of thermal protection system, since to re- sist thermal impact requires a material of higher density, whilst to retard heat transmission re- quires a material of lower density. If a heat protection system is constructed in two layers, each serves a particular purpose, together they could satisfy the entire heat protection requirements. The thickness of the two layers can be adjusted through mathematical manipulations to give a good result in weight and economy. The above procedure, called integrated design procedure of the heat protection system, is presented in this paper.