Experimental study of a ventilated supercavitating vehicle model in a high-speed water tunnel

To investigate the evolution of cavity morphology and the ventilation characteristics of ventilated supercavitating vehicles, a scaled-model experiment was conducted in the high-speed water tunnel at the China Ship Scientific Research Center. High-speed photography, pressure measurements, and flow rate control were employed to capture the cavity boundary profiles and the corresponding cavitation numbers under various ventilation parameters. The effects of the cavitator rudder angle and tail fins on the cavity morphology and ventilation characteristics were systematically analyzed. The results indicate that when the dimensionless ventilation coefficient C q is below 2, the cavity size increases rapidly with the ventilation rate; when C q ​exceeds 4, further increases in the ventilation rate have a negligible effect on the cavity size. The cavitator rudder angle deforms the cavity cross-section, and the vertical diameter can be corrected using the cos δn law. The cavity axis offset agrees well with theoretical predictions after introducing a correction factor k δ = 1.25. The presence of tail fins dramatically raises the minimum ventilation coefficient required for complete cavity envelopment, from 0.28 to 3.68. Based on the experimental data, an empirical formula for the ventilation characteristics that incorporates the effect of tail fins is derived. This study provides a basis for the design of ventilation parameters and the prediction of cavity morphology for supercavitating vehicles.