周期性来流扰动对通气超空泡航行体流体动力特性的影响

The influence of periodic inflow disturbances on the hydrodynamic characteristics of ventilated supercavitating vehicles was studied by using the sliding grid method. Two hydrofoils were arranged to swing in opposite directions at the front of the computational field in order to produce an inflow condition of horizontal velocity periodical fluctuation. The influence of periodic inflow on the multiphase flow of the ventilated vehicle was investigated. The results show that: under the influence of periodic horizontal flow, the cross-section of the ventilated supercavitation will shrink, and the vehicle is prone to produce wetted areas, which will affect the drag reduction effect of cavitaty. The changes of hydrodynamic characteristics of the vehicle under the action of periodic inflow were analyzed, and it is found that when the vehicle is completely wrapped by the cavity, the resistance presents periodic fluctuation and the lift becomes small. When the vehicle is partially wrapped by the cavity, the resistance will be reduced due to the fluctuation of the flow velocity, and the lift will fluctuate greatly. The influence of the wavelength and amplitude of the periodic inflow on the cavity shape was analyzed according to the wetted area ratio. The influence of the wavelength and amplitude of the periodic inflow in the horizontal direction on the shape of the ventilated cavity was also given.