Water Tunnel Experiment Research of Ventilated Cavitation Drag Reduction Technology for a High Speed UUV

A high speed unmanned underwater vehicle (UUV), configurated by a cavitator, strakes and an ellipsoid streamline body, is put forward based on ventilated cavitation technology for the demand of drag reduction. The ventilated cavitation and hydrodynamic characteristics of the configuration are analyzed by water tunnel experiments. The experimental results show that the strakes can divide the cavitator-formed cavity into the upper and the lower parts. The two parts of cavity develop almost in an independent way, almost without any interference, among the range of experimental model size. Half cavity can be formed when the upper and the lower holes are ventilated asynchronously, which keeps a wet surface area of the model. Ventilated cavitation can greatly reduce the model resistance. Drag reduction rate increases with the value of Froude number. The maximum drag reduction rate can be about 50% within the range of the experimental Froude number. When it is unilaterally ventilated, or the upper and lower cavities aren't merged at the tail of the model, the model is acted by a positive vertical force which can support the gravity of the model itself.