Numerical Study On Effect Of Ventilation Parameters On Hydrodynamic Characteristics Of Submaring-launched Vehicle

As a kind of underwater weapons, submarine-launched vehicle has a stronginvisibility, mobility and attack capability. During the process of a vehicle’sunderwater movement, the environmental pressure is declining, the flowcharacteristics is constantly changing, and always accompanied by the phenamenonof caviating flow.Cavitating flow is a complicated phenomena, including unsteady,turbulence and phase-transition, and so on. In order to achieve the effect of enhancecavitation that it is need to ventilate for submarine-launched with low velocity,which makes the liquid medium transiting for gas-vapour-liquid three phases, but itwill bring great difficulty to numerical study on the cavitation multiphase flow ofthe vehicle. This paper focuses on the numerical study on effect of ventilationparameters on hydrodynamic characteristics of submarine-launched vehicle with theproblemof multiphase flow of the vehicle during the movement underwater. Themain research work are as follows:Inroducing the numerical simulation for the ventilated cavitating flow,including the theory equation of the Mixture homogeneous equilibrium floe modelthe turbulence model, the cavitation model and wall function. A numerical method isproposed to calculate the ventilation cavitating flow of submarine-launched, and thenumerical simulation method is validated by comparing the result of numericalsimulation to the result of experiment.The numerical simulation is carried out to study on the cavity shape and thehydrodynamic of submarine-launched vehicle under the circular ventilation, andobtains the influence laws of ventilation mass flow, ventilation angles andventilation positions for the cavitation shape and the hydrodynamic by analying thecavitation shape, the surface pressure, drag force changing with different ventilationparameters.The numerical simulation is carried out to study on the cavity shape and thehydrodynamic of submarine-launched vehicle under the hole ventilation, and obtainsthe influence laws of the number of ventilated holes and the hole diamter for thecavitation shape and the hydrodynamic by analying the cavitation shape, thepressure around the body, drag force changing with different ventilation parameters.Finally, compares and analysis the differences between the two kinds of ventilation.