封闭水域内固体火箭发动机尾流结构数值研究

In order to investigate the wake field characteristics of underwater solid rocket motor in confined space, three-dimensional model was established for numerical studies which neglected the heat and mass transfer process between gas and water, and body forces such as gravity and buoyancy. Realizable k-ω turbulence model and VOF(Volume of fluid) multi-phase model were adopted to get the simulation results of solid rocket motor working process in confined space with different water depths. The gaseous jet feature of wake flow field beyond the nozzle exit was analysed and the oscillation of pressure on experimental water tank was monitored. The results indicate that the simulation results of the three-dimensional model are consistent with the experimental results. The shape of gas bubble and the pressure change rule of gaseous jets injected into water in confined space are non-axisymmetric. The unstable shock wave motion in the central gas path is macroscopically characterized by the unstable bulging of the jet interface and the backward displacement of the bubble neck. The deeper the water is, the greater the pressure of the tank wall near the nozzle exit is. The tank wall is more susceptible to low-frequency and small-amplitude pressure oscillation under high back pressure.