Owing to the complex mesoscopic structures, 3D braided charring composites for the thermal protection system (TPS) have the multi-scale and multi-physical high-temperature responses. The mesoscopic features can significantly affect the volumetric ablative behavior of the braided composites, which will be essential for the TPS design. To take into account the effect of mesoscopic structures on the volume ablation response, the thermo-physical properties of constituents within the braided composites are predicted using asymptotic averaging method. The volumetric ablation model of the braided composites considering the mesoscopic structures is proposed, which is calculated by finite volume method with a tightly coupled solving process. The effect of braid angles on the volumetric ablation responses of the braided composites are investigated. The maximum back temperature and the peak inner pressure of the braided composites decrease with the increase of the braid angle. The isothermal and isobaric surfaces of the braided composites under volumetric ablation exhibit complex characteristics and are not perpendicular to the heating direction, which may induce the complex thermal stress field within the composites. The study on mesoscopic volume ablation may be helpful to accurately predicting the ablation responses and guiding the material design of the braided charring composites.

由于复杂的介观结构，用于热保护系统（TPS）的3D编织炭化复合材料具有多尺度和多物理的高温响应。介观特征可显着影响编织复合材料的体积消融性能，这对于TPS设计必不可少。考虑到介观结构对体积消融反应的影响，使用渐近平均法预测了编织复合材料中各成分的热物理性质。提出了考虑介观结构的编织复合材料的体积烧蚀模型，该模型通过有限体积法并采用紧密耦合的求解过程进行计算。研究了编织角对编织复合材料体积消融响应的影响。编织复合材料的最大背温和峰值内部压力随着编织角的增加而降低。体积烧蚀后的编织复合材料的等温和等压表面表现出复杂的特性，并且不垂直于加热方向，这可能会在复合材料内引起复杂的热应力场。介观体积烧蚀的研究可能有助于准确地预测烧蚀响应，并为编织炭化复合材料的材料设计提供指导。这可能会引起复合材料内部复杂的热应力场。介观体积烧蚀的研究可能有助于准确地预测烧蚀响应，并为编织炭化复合材料的材料设计提供指导。这可能会引起复合材料内部复杂的热应力场。介观体积烧蚀的研究可能有助于准确地预测烧蚀响应，并为编织炭化复合材料的材料设计提供指导。