Research On The Shapes Of The Ventilated Supercavity Base On Multiphase Model

There are two ways to produce supercavity which is composed of the vapor or the gas. One is the vaporization caused by the high speed flow when the local pressure falls below a saturation value. The other is the ventilation by injecting gas. When the cavity length approaches or exceeds the character length, a supercavitating flow occurs. It results in the multiphase flow of gas, vapor and water in the near-wall region of underwater vehicle except its head which touches with water only. The ventilated supercavitating flow relates to the complex flow phenomenon and mechanism, such as multiphase flow, turbulence, mass transfer, compressibility and unsteadiness.In this dissertation, some key problems about ventilated cavitating flow, including the cavity morphology, were investigated using the theoretical analysis, mechanical test and numerical simulation.First, this article has done the preliminary research about the ventilated cavity model and the corresponding computational method, study the two-phase and three-phase cavity flow mathematical model of FLUENT, choose a suitable solution to the model established by the method of calculation equation and the corresponding turbulence model and wall approach.Second, the paper analyse the effect on the morphology of cavity about the tail support, the turbulence model, the turbulent parameters of the boundary conditions, the Not Condensing Gas of natural cavity model; Simulate the spatio-temporal evolution process of a three-phase ventilation cavity flow.Finally, the relations between the shapes of ventilated supercavitation and ventilation rates were obtained through numerical simulations. At the same time, the corresponding experiments were performed. Then the differences between the simulated results and experimental results were analyzed and discussed through comparing the data obtained in the paper.