水下点火固体火箭发动机两相流流场数值分析

利用FLUENT软件,使用湍流模型和VOF(volume of fluid)模型对水下点火固体火箭发动机的气液两相流场进行数值分析,对点火初期喷管中燃气的流动过程和燃气泡的发展过程进行了仿真,数值模拟了固体火箭发动机尾流场燃气密度、压力和温度的分布规律。研究表明:点火初期,喷管内流场将有一个完整激波建立的过程,除此之后的喷管尾流区域,由于气体受到压力扰动的影响,激波结构被破坏,没有形成连续的膨胀—压缩波；射流过程中燃气泡头部一直保持较大直径,中部燃气通道存在随轴向周期性的膨胀-压缩现象；喷管尾流区,各流动参数出现不同程度的振荡现象:喷管出口燃气密度受外界水的压缩及传质传热的影响,出现峰值后逐渐稳定；喷管出口燃气总压由于受水环境的急剧压缩,在喷管出口附近形成一个高压区；喷管出口燃气温度经三次周期变化后,温度逐渐降至1750K以内。 

Numerical analysis for underwater ignition two-phase flow field of solid rocket motor

Two-phase gas-liquid flow field in the underwater ignition process of solid rocket motor was numerically solved by using FLUENT software, turbulence model and VOF (volume of fluid) model. The flow process of gas and the development process of gas bubble at the beginning of ignition were analyzed.The distribution of gas density, pressure and temperature in the wake flow field was numerically simulated. The study showed that:at the beginning of ignition,a complete shock wave was established in the nozzle, after which the mechanism of shock wave was destroyed.No continuous expansion-compression waves were formed because of the gas was affected by pressure disturbances;the gas bubbles head was kept at a large diameter, and the middle gas channel had a periodic expansion-contraction;the parameters had different degrees of shock phenomenon:the wake flow field of the gas density greatly changed at the exit of nozzle with the reason for compression of the water and the increasing quality of gas; the total pressure of the outlet of the nozzle was drastically compressed by the water environment, forming a high pressure zone at the exit of the nozzle; the gas temperature reduced to 1750K or less gradually after three cycles of change.