目的 提高C/SiC材料发动机喷管的高温抗烧蚀性能。方法 基于质量、能量守恒和物性方程建立发动机喷管内燃气湍流模型，应用数值模拟方法计算喷管基体和各涂层的线烧蚀速率，并验证模型的准确性。通过比较不同种类涂层的抗烧蚀性能及涂层间匹配性，建立多元复合涂层体系，分析体系烧蚀行为及烧蚀机理，对HfO2-ZrC-SiC-C/SiC四元体系在不同温度下的线烧蚀速率进行计算。结果 Hf系、Zr系涂层抗氧化烧蚀性能优异，最大线烧蚀速率皆处于0.3~1.2 μm/s之间。HfO2具有良好的抗烧蚀性能和自身稳定性。相较其他体系，HfO2-ZrC-SiC-C/SiC体系喷管的喉部及扩散段线烧蚀率更低。体系在7 MPa下，分别在1700、2100、2500、2900 K计算了线烧蚀速率，最大线烧蚀速率区域产生了迁移现象，各温度梯度线烧蚀速率分别提高了174%、20.22%、18.04%。结论 HfO2能够有效地降低喷管收敛段的烧蚀速率，且适合作为复合涂层体系最外层。温度升高明显加剧了化学反应烧蚀和机械剥蚀，高温度下机械剥蚀是烧蚀的主要因素。

The work aims to improve the ablation resistance of C/SiC engine nozzle. The turbulence model of engine nozzle was established based on mass, energy conservation and physical property equation. The linear ablation rate of nozzle substrate and each coating was calculated by numerical simulation method, and the accuracy of the model was verified. Multi-component composite coating system was established by comparing the ablation resistance of different types of coatings and the coating matching. The ablation behavior and ablation mechanism of the system were analyzed to calculate the linear ablation rate of HfO2-ZrC-SiC-C/SiC Quaternary system at different temperature. The oxidation ablation performance of Hf and Zr coatings was excellent, and the maximum linear ablation rate was between 0.3~1.2 μm/s. HfO2 had good ablation performance and stability. The ablation rate at the throat and diffusion section of HfO2-ZrC-SiC-C/SiC system was lower compared with other systems. At 7MPa, the linear ablation rate was calculated at 1700 K, 2100 K, 2500 K and 2900 K, and the maximum linear ablation rate region was migrated. The ablation rate of each temperature gradient respectively increased by 174%, 20.22%, 18.04%. HfO2 can effectively reduce the ablation rate of the convergent section of the nozzle and is appropriate for being used as the outermost layer in the composite system. In addition, the increase of temperature significantly aggravates the ablation of chemical reaction and mechanical denudation, and mechanical denudation becomes the main ablation mechanism at high temperatures.