再入飞行器烧蚀热防护一体化计算方法

针对再入飞行器烧蚀热防护系统烧蚀与瞬态温度耦合响应预测问题，提出了一体化计算方法，为再入飞行器烧蚀热防护设计提供包括气动热、烧蚀后退、瞬态温度响应在内的动态响应预测依据。该方法采用Sutton-Graves和Tauber-Sutton理论计算驻点的对流热流和辐射热流，通过表面能量平衡整合具有较高精度的烧蚀模型，并通过Landau变换简化烧蚀后退带来的节点删除过程并保证空间离散精度，最后求解瞬态有限差分热传导方程获得烧蚀热防护系统的热环境、烧蚀过程和温度响应。通过对比计算碳-碳材料钝头体地球再入过程和酚醛浸渍基碳烧蚀体（PICA）材料电弧风洞烧蚀模拟，对该方法对于不同材料体系的适用性进行了验证。计算结果表明：对于密度较高的碳-碳材料，本文计算结果与经典的热平衡积分法吻合较好，偏差在7%以内；而对于低密度材料（如烧蚀性能对压力高度敏感的PICA材料），随着热流和压力的增大，预测偏差逐渐增大。所提出的方法实现了气动热、烧蚀、瞬态温度响应耦合过程的一体化计算，在保证精度的前提下实现快速计算分析，为再入飞行器烧蚀热防护设计提供依据。

Integrated computing method for ablative thermal protection system of reentry vehicles

To predict the coupled response of ablation and transient temperature in the ablation thermal protection system of reentry vehicles, an integrated computing method is proposed to provide the dynamic response prediction basis for the design of ablation thermal protection of reentry vehicles, including aerodynamic heat, ablative recession and transient temperature responses. The method adopts the Sutton-Graves and Tauber-Sutton theory to calculate the convection heat flux and radiation heat flux of the stagnation-point. Through the surface energy balance, an ablation model of high precision is integrated. The Landau transformation is introduced to simplify the node removal process caused by surface ablative recession, meanwhile ensuring the space discrete precision. The transient heat conduction equation is solved by the finite difference method, obtaining the heat environment, ablation process and temperature response for the ablative thermal protection system. The applicability of the proposed method to different material systems is verified by comparison of two simulation examples: the atmospheric reentry process of carbon-carbon blunt body, and the Phenolic Impregnated Carbon Ablator(PICA) ablative materials arc wind tunnel simulation. The calculation results show good agreement with the classical thermal equilibrium integral method, with an error smaller than 7%. However, for low-density materials (such as PICA materials whose ablative properties are highly sensitive to pressure), the prediction deviation increases with the increase of heat flux and pressure. The proposed method realizes integrated calculation of aerodynamic heat, ablation and transient temperature response in the coupling process, and fast calculation on the premise of accuracy ensurance, thereby providing a basis for the design of ablative heat protection of reentry vehicles.