Charring composites can provide the most efficient thermal protection shield for the thermal protection system (TPS), which is essential for hypersonic reentry vehicles. It is of great importance to clarify the implication of different porosity configurations of charring composite on the bondline temperature. In the present study, a one-dimensional transient thermal model considering the pyrolysis without the surface recession is built and validated. Based on this model, the thermal protection performance of various porosity distribution design schemes is analyzed when keeping the total pore volume unchanged. The present results show that the scheme with the linear increasing porosity from the bondline to the heated surface can decrease the bondline temperature by 7.8 K and 15.8 K compared with the homogeneous scheme and the linear decreasing scheme, respectively. Further, a scheme with parabolic increasing distribution of porosity are evaluated. It is found that it can reduce the bondline temperature by an additional 2.9 K.

炭化复合材料可以为热保护系统（TPS）提供最有效的热保护罩，这对于高超音速再入飞行器至关重要。阐明炭化复合材料的不同孔隙率配置对粘合层温度的影响具有重要意义。在本研究中，建立并验证了一个考虑热解而没有表面衰退的一维瞬态热模型。基于该模型，分析了不同孔隙率分布设计方案在总孔容不变的情况下的热防护性能。目前的结果表明，从粘合层到加热表面的孔隙率线性增加的方案可以将粘合层温度降低 7.8 K 和 15。8 K 分别与同质方案和线性递减方案相比。此外，评估了具有抛物线增加的孔隙率分布的方案。发现它可以将胶层温度额外降低 2.9 K。