Cavitation/ventilation phenomena during the water impact with horizontal velocity of double curvature shaped bodies

The role played by the rear body curvatures on the generation of cavitation and ventilation phenomena during the water impact at high horizontal velocities is investigated experimentally. Pressures and loads are measured during the tests and the interpretation of the data is supported by underwater images. Different cavitation/ventilation modalities have been observed, with the change from one to the next occurring with velocity variations of few m/s. It is found that the phenomenon is mainly governed by the longitudinal curvature. For the sharper curvature shapes cavitation starts around 30 m/s whereas smoother shapes shift the transition to about 40 m/s. Based on the hydrodynamic loads measured at fore and aft positions, it is seen that the occurrence of cavitation and ventilation affect the position of the center of loads, thus implying that in free fall conditions the occurrence of cavitation or ventilation may influence the body dynamics.