Abstract:

A mathematical model of unsteady ventilated supercavitation is established based on the princi- ple of Logvinovich of the cavity sections expansion and mass conservation equation. The mathematical model is used to simulate the shape stability of ventilated supercavitation under the disturbances of air- supply rate, cavitator, velocity and some combination perturbation, respectively, and then the stability of ventilated supercavitation is analyzed. The results indicate that the disturbance of velocity plays a crucial role in the shape stability of ventilated supercavitation, and the oscillation of cavity is strong, the disturb- ance of cavitator can influence the shape stability of ventilated supercavitation with low-amplitude and de- termine the last length of cavity, the disturbance of air-supply rate is small compared with the others and can be ignored when they exist.

Key words: fluid mechanics, multiple disturbance, cavity stability, the principle of Logvinovich of the cavity sections expansion, ventilated supercavitation, unsteady flow