固体火箭发动机碳基材料喷管热化学烧蚀特性

为了准确预示固体火箭发动机碳基材料喷管的烧蚀率,依据热化学烧蚀理论,建立了喷管传热烧蚀的二维轴对称气-固-热耦合计算模型,计算通过FLUENT壁面化学反应模型完成,无需事先假设烧蚀控制机制。针对70-lb BATES发动机喷管进行了烧蚀计算,研究了推进剂配方、氧化性组分、燃烧室压强对喷管烧蚀的影响。结果表明:烧蚀率计算值与试验测试值吻合较好;烧蚀率分布遵循喷管内壁热流密度分布规律,在喉部上游入口处达到峰值;烧蚀率随推进剂Al含量增加而降低,随燃烧室压强升高而近似正比例增大;H2O是决定烧蚀的主要氧化性组分。

Carbon-Based Nozzle Thermochemical Erosion Characteristics in Solid Rocket Motors

Based on the thermochemical erosion theory,a two-dimensional axisymmetric,coupled gas-solid-thermal numerical framework was established to predict the carbon-based nozzle erosion in solid rocket motors.Numerical simulations were carried out using the Wall Surface Reaction model of the commercial code FLUENT and the assumption whether the erosion process was chemical kinetics or diffusion controlled was not needed.The method was introduced to simulate the 70-lb BATES motor nozzle erosion and examine the effects of propellant composition,oxidizing species and chamber pressure.The calculated results agree well with experimental data.The erosion rate follows the trend exhibited by the heat flux distribution,and peaks slightly upstream of the throat.The erosion rate decreases with increasing aluminum content and increases almost linearly with chamber pressure.H2O is the dominant oxidizing species in dictating nozzle erosion.