环境压强连续变化作用下水下燃气射流数值仿真

Numerical Simulation of Underwater Gas Jet Fields with the Continuous Change of Ambient Pressure

深海反潜导弹在水下航行过程中会经历大幅度的水深变化,伴随着环境压强的连续变化,反潜导弹水下固体火箭发动机的水下燃气射流结构与工作特性具有重要的研究意义。文中采用液体体积多相流模型,结合用户自定义函数和动网格技术,建立了水下固体火箭发动机轴对称动态模型,对水下发动机沿垂向运动至250 m水深过程进行数值仿真。仿真结果表明,在水下运动过程中喷管尾部燃气射流不再出现断裂与回击等现象,在超音速射流建立过程中,激波逐步推出喷口,最终形成位置固定的锥形激波;在100 m水深以下,燃气射流流场特性受环境压强的影响较大,呈现较强的压缩性;在大航速200 m/s速度航行时,射流梗阻效应减弱,使得水下发动机工作性能受到环境压强的作用较小。文中研究可为水下发动机深水垂向运动工作性能提供参考。

Deep-sea antisubmarine missiles undergo significant changes in water depth during underwater navigation. It is of great importance to study the structure of the gas jet and working characteristics of the underwater solid propellant rocket engine of antisubmarine missiles during continuous changes in environmental depth pressure. Utilizing the volume of fluid(VOF) multiphase model, this study combines the user-defined function(UDF) with the dynamic mesh technique to establish an axisymmetric dynamic model of an underwater solid propellant rocket engine, as well as simulates the process of vertical motion of the underwater engine to a depth of 250 m. The results show that the gas jet no longer breaks and strikes back at the end of the nozzle during underwater motion. During the formation of the supersonic jet, the shock wave is gradually pushed out of the nozzle outlet, and finally, a conical shock wave with a fixed position is formed. Below a depth of 100 m, the flow field characteristics of the gas jet are significantly affected by the ambient pressure, and the flow field structure shows apparent compressibility. At a speed of 200 m/s, the gas jet obstruction effect is weakened, which reduces the effect of the ambient pressure on the working characteristics of the underwater engine. The study of the flow field characteristics of underwater gas jets subjected to continuous changes in ambient pressure can provide a reference for exploring the working performance of underwater engines in deep-water vertical motion.