潜航飞行体深水超音速气体射流的流动稳定性研究

The reliability and stability of underwater solid rocket motor propulsion system are crucial to the ballistic accuracy and flight stability of submarine vehicles. The working process of the motor is the flow process of typical supersonic gaseous jets underwater. A planar vertical two-dimensional jet geometric model is established, and the detached-eddy simulation turbulence model is used to simulate and analyze the flow field of supersonic gaseous jets in deep-water, and the oscillation characteristics of parameters in the flow field are monitored and analyzed. The underlying flow mechanism due to thrust oscillation of underwater solid rocket motor is addressed. The results show that a high-frequency oscillation occurs in the gas wake of the underwater solid rocket motor, and is accompanied by a high-amplitude intermittent oscillation. The oscillation is related to the unstable motion of shock waves along the central gas path, which leads to a sharp oscillation of pressure in the tail space, ultimately causing thrust instability. The analysis of thrust oscillation characteristics indicates that the deeper the water depth is, the larger the thrust oscillation amplitude is, and the higher the frequency is; and the larger the diameter of wall at nozzle exit is, the larger the thrust oscillation amplitude is, and the higher the frequency is.