Modeling of Supercavitating Flow over Submerged Vehicles

Supercavitation occurs when a submerged and moving body is enveloped by a large and continuous cavity. Research on the characteristics of supercavitation have received great attention due to its substantial effect on drag reduction, as compared to the same fully wetted underwater body. In this study, numerical simulation of ventilated and natural supercavitation in an axisymmetric vehicle with cavitator is performed. In addition, simulation was performed for three-dimensional cases with various cavitator sizes. Also, the relations among cavity shape, ventilated cavitation number, and ventilation rate, for different cavitator sizes, were analyzed. Furthermore, the numerical simulation was performed on an underwater vehicle with disk cavitator at nose at various installation angles. The effect of installation angle on the supercavity formation was also studied. The multiphase mixture method was used and the Rayleigh-Plesset equation was implemented for inter-phase mass transfer. The numerical results were compared with experimental data and show equivalent natural and artifitial cavity sizes.