Experimental Analysis of the Characteristics of Both the Natural and Ventilated Supercavities behind a 30 Degree Conical Cavitator

In this paper، the characteristics of both the natural and ventilated supercavities occurred behind a 30 degree conical cavitator were investigated experimentally. For all cases، the drag force of the cavitator and the streamwise distribution of pressures downstream of the cavitator were measured using the corresponding electronic devices. Both of the maximum diameter and the length for the supercavities، formed behind the cavitator، were measured from the captured pictures using a high speed camera. Experimental results of France and Michel reported for natural supercavitation flow over a flat disk was utilized for validating the present test setup. For the natural supercavitating cases، the results show that the lengths of supercavities decreased as the inlet velocity decreased، while their lengths were many times shorter than those related to the ventilated cases. Also، the sensitivity of the length of the supercavities to the inlet velocity of flows was reduced for the ventilated cases. For the ventilated cases، the lengths of supercavities were influenced most by the mass flow rate of the injected air.