Influence of cavitator parameters on formation and development of supercavity

Based on the way how to form supercavity, a series of projectile experiments and moderate-speed tunnel experiments were carried out to study the formation and development of the natural and ventilated supercavities. The processes of forming supercavities were recorded and discussed. The influence of cavitator parameters on the critical cavitation number and critical ventilation coefficient was analyzed. Qualitative features of the supercavity size change were obtained. It is shown that the cavitator diameter and coutour have a similar influence on the natural and ventilated supercavity sizes. Supercavity size increases with the increase of cavitator diameter and the formation of supercavity for a blunt cavitator is easier than that for a cone cavitator under the same condition. A cavitator of relatively small diameter might not be able to form a ventilated supercavity, mainly because the natural cavitation number is not small enough. Furthermore, the research shows that the cavitator diameter has an important effect on the fineness ratio of the ventilated supercavity, which is not the same as the natural supercavity. Finally, the perspective future research on cavitators is discussed.