Development of ventilated cavitation and its effect on hydrodynamics

Development of the ventilated cavitation and its effect on hydrodynamics have been studied through a series of water tunnel experiments. The investigation shows that the ventilated cavitation goes through the phases of partial cavitation and supercavitation, the reentrant jet behaves differently in these two phases, and the transition criterion between them can be achieved from the notable change of cavitation. Cavitation number and model drag decrease with the increasing ventilation rate in partial cavitation phase, they decrease abruptly in transition phase if the ventilation rate increases just a little, and they keep almost unchangeable in supercavitation phase with the increase of the ventilation rate. The instabilities of ventilated cavitation behave oscillatory and fluctuant, they will result in the instability of model dynamics. These experimental results are valuable to the control of supercavition.