Research On High-Speed Gas Jet Of Nozzle Underwater

The generation of high-speed gas jet of rocket nozzle underwater after the ignition moment consists of more complicated and special phenomena than the situation on the ground, such as the formation of the gas bubble after the nozzle and the wave structure's generating and moving etc. The tracking of free interface between phases in multiphase flow using finite volume method is now one of the research focuses in computational fluid dynamics. Most general CFD software consists of this kind of algorithm. Among them, Fluent is the most powerful and popular one, which is wildly used in industry and has solved many problems concerned. But for the point of high-speed gas jet underwater, there is no existing successful case. With Fluent's advanced features addressing gas-liquid multiphase flows and the aid of the external user-defined-functions(programs) linked to the software, it is possible to solve the problem above sufficientlyResearch on high-speed gas jet of a nozzle underwater by an entirely new method is presented in this paper. Using Volume of Fluid technique based on Finite Volume Method to solve the time-dependent multiphase flow including compressible phase is the main contribution of this paper. Numerical result shows that the calculation can successfully simulate the formation of the gas bubble after the nozzle and capture the wave structure in the highly compressed gas.Additionally, The paper introduces the pressure-linked method of continually equation based on half-staggered grids to solve flow over axis metric body in internal and external flow situation, solves the same problem using FVM method on staggered grids and compare the results to get the solution rule.