燃气流气动加热环境中碳基复合材料烧蚀传热特性分析

A calculation analysis for the ablation and heat transfer of carbon-based composite materials in combustible airflow environment

为研究燃气流气动加热环境中碳基复合材料的烧蚀传热特性,通过燃气流环境中碳基复合材料的化学反应、热化学烧蚀以及热响应模型分析,建立相应的烧蚀传热计算模型,对比燃气流平板及驻点烧蚀试验的烧蚀量试验与计算结果,两者吻合较好.在此基础上,分析燃气流与空气环境中碳基复合材料烧蚀传热特征的差异,以及燃气组分、压力等参数变化对碳基复合材料烧蚀传热特性的影响.研究表明,在同样的热环境条件下,燃气流环境下的材料表面温度低于空气环境下的结果,烧蚀后退量高于空气环境下的结果;表面温度和烧蚀后退量分别随着H_2O和CO_2含量的增加呈现减小和增大的趋势,H_2O的影响程度更大.

To study the ablative heat transfer mechanisms of carbon-based composite materials in the aerodynamic heating environment of combustible airflow, an analysis of chemical reaction, thermal chemical ablation and thermal response for the materials was conducted,and a calculation method for the oxidative ablation and heat transfer of the materials was present. The comparison results signified that the ablation results obtained by the calculation method were consistent with the experimental results of flat and stagnation-point ablation tests. Using this method, the ablation and temperature-field differences of carbon-based composite materials in combustible airflow and air environments, and the effects of a variety of parameters concerning pressure and components on the ablation and heat transfer were obtained. In the same thermal environment, the material surface temperature under combustible airflow is lower than that of the air environment, and the ablation back quantity is higher than the results of the air environment; with the increase in H20 and CO2 content, surface temperature and the amount of ablation back show atendency of decrease and increase, respectively, with H2O exhibiting a greater influence.