炭化材料烧蚀防热的理论分析与工程应用

本文重点对炭化材料烧蚀防热的内部机理，即存在非平衡化学反应的热解气体扩散通过变孔隙度的多孔介质的瞬态传热、传质过程做了深入分析，并利用该方法对飞船返回舱头部的再入烧蚀性能进行了一维计算，通过与简化模型的计算结果比较表明：材料内部质量沉积和化学反应对烧蚀性能有较大影响。

An Analysis of a Charring Ablative Thermal Protec-tion System with Its Engineering Applitcaion

This paper presents a general analysis about the transient response of a charring ablative thermal protection system undergoing ablation,including a detailed treatment of the various thermal,cher-mal,and mass transfer processes in ablation. Three types of thermoche-mical ablative mechanism are presented due to surface temperature.The mathematical equations are presented for the in-depth thermal response problem which is considered as a transient heat and mass transfer pro-cess with a multicomponent flow of pyrolysis-gases undergoing non-e-quilibrium chemical reactions through a variable porous medium which isitself undergoing pyrolytic reactions.The equations are solved numeri-cally by using an exponential finite-difference scheme to obtain solu-tions of a reentrv command module for the thicknesses of the charredlayer and pyrolysis-zone,surface-recession, surface temperature history,profiles of internaI temperature,pressure and solid density,et al.,Aiso, results shown here compare numerical solutions from thisanalysis with solutions from a previous analysis which did not treat thechemical and mass transfer processes as thoroughly as this analysis. This analysis predicts that the surface temperature,surface-recession,gradient of internal temperature are greater than those indicated by theprevious analysis,while the thickness of pyrolysis-Zone, back walltemperature rise are lower,These differences result from considerationof pyrolyss-gases deposition in this analysis.