基于气固两相双流体模型研究火箭发动机斜切喷管流场特性

为了研究火箭发动机(SRM)斜切喷管的两相流动特性,采用气体-颗粒相双流体模型,并结合多区域混合网格技术,对发动机斜切喷管内气相与颗粒相的相互作用规律进行研究,探索颗粒直径与颗粒质量分数变化对发动机喷管气固两相流动特性的影响。结果表明:固体颗粒相的存在,对发动机斜切喷管的流场结构产生重要影响,导致喷管轴线附近存在一个燃气流动速度较低,温度较高的区域。同时,喷管壁面附近存在无粒子区,随着颗粒直径的增加,无粒子区域的范围逐渐扩大。并且,颗粒直径越大,其运动速度越小,在喷管内的滞留时间越长。颗粒直径与质量分数的变化同样会影响发动机喷管的流场结构,随着颗粒直径的增加,发动机喷管轴线处气相马赫数先减小后增大,而燃气温度则先增大后减小;发动机推力的变化趋势与马赫数变化趋势相同,但两者并不同时达到极值点。颗粒相的质量分数越大,沿喷管轴线方向的气相马赫数和发动机推力越小,喷管两相流损失越大。

Flow field characteristics of angle-cut nozzle of solid rocket motor based on gas-solid two phase flow model

In order to study the two phase flow characteristics of angle-cut nozzle of solid rocket motor (SRM), a gas-particle two-fluid model was adopted and combined with multi-region hybrid grid technology, and the interaction between gas phase and particles in the scarfed nozzle of solid rocket motor was researched. The effect of particle diameter and mass fraction on the gas-solid two phase flow characteristics of angle-cut nozzle was also investigated. Results showed that, the existence of solid particle phase had an important effect on the flow field structure of gas phase for angle-cut nozzle of SRM, bringing about a region with low velocity and high temperature of gas flow near the nozzle axis. At the same time, there was an area near the nozzle wall without particles. With the increase of particle diameter, the region gradually expanded without particles. The larger the particle diameter, the smaller the velocity; and the detention time was longer in the nozzle. The change of particle diameter and mass fraction also affected the flow field structure of rocket nozzle, with the increase of particle diameter, the gas phase Mach number first decreased and then increased along the nozzle axis, and the gas temperature first increased and then decreased, the trend of engine thrust was the same as that of Mach number, but both of which did not reach the extreme point simultaneously. The larger the particle mass fraction, the smaller the gas phase Mach number along the nozzle axis and the value of engine thrust; and the loss of two phase flow in the nozzle was larger.