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为了数值模拟包含气体分子和凝相颗粒的两相羽流场,使用自主开发的羽流计算软件(PWS)对两相作用模型进行研究。计算均匀气流对颗粒的加速过程,结果与理论解一致,证明气体分子对颗粒的单向作用模型合理。计算气体分子在颗粒表面的反射时,将全局坐标系转换到颗粒坐标系确定其法线,再转换到法线坐标系进行镜面反射或漫反射。将这种间接法与使用反射向量的分布函数的直接法进行了对比。对同一个气体分子在颗粒表面的反射进行1×106次数值试验,两种方法所得镜面反射的速度向量均符合空间均匀分布,漫反射的速度向量分布相互一致。使用两种方法模拟150N液体火箭发动机的两相羽流场,所得气相羽流场几乎相同,间接法计算效率较高。液滴颗粒对气流场的影响主要集中在轴线附近,与无液滴的气流场相比,有液滴时会使气流温度升高、压强增大、马赫数减小。
In order to numerically simulate a two-phase plume flow field containing gas molecules and condensate particles, a two-phase interaction model was studied using a self-developed plume calculation software (PWS). Calculate the acceleration of uniform airflow on the particles, the result is consistent with the theoretical solution, which proves that the unidirectional model of gas molecules on particles is reasonable. When calculating the reflection of gas molecules on the particle surface, the global coordinate system is converted to the particle coordinate system to determine its normal and then converted to the normal coordinate system for specular reflection or diffuse reflection. This indirect method is compared with the direct method using the distribution function of the reflection vector. 1 × 106 numerical experiments on the reflection of the same gas molecules on the surface of the particles were carried out. The velocity vectors of the specular reflection obtained by the two methods all fit the spatial uniform distribution, and the velocity vectors of the diffuse reflection are consistent with each other. Two methods were used to simulate the two-phase plume of 150N liquid rocket engine. The resulting gas-plume fields were almost the same, and the indirect method was more efficient. The influence of droplet particles on the flow field is mainly concentrated near the axis. Compared with the droplet-free flow field, droplet increases the temperature of gas flow and the pressure increases, and the Mach number decreases.