Analysis of the effect of underwater supersonic gas jet on the ventilated supercavitation flow

A high-fidelity numerical model is employed to investigate the effect of underwater gas jet on ventilated supercavitation flow characteristics. The model includes the compressibility of gas phases and utilizes the inhomogeneous multiphase model and SST k−ω turbulence model. The developed solver is quantitatively validated by experimental results. Supercavity-jet interactions are examined under various flow conditions. The effect of underwater gas jet on the supercavitation flow is contingent upon the type of ventilated supercavities. In the case of the wake-closure flow pattern, the ventilated supercavity fully envelops the nozzle, and variations in the supercavity geometry depend on different jet momentums, the corresponding mechanism has been revealed from the perspective of the supercavitation flow structure and gas leakage behavior. When the supercavity dimension is insufficient to fully envelop the nozzle due to the angle of attack, gas jets are injected directly into the surrounding water, resulting in intense pulsations of the underwater supersonic gas jet that impact upstream dynamics of supercavitating flow fields. Increasing the ventilation rate can effectively mitigate severe oscillations in supercavitating flow fields and minimize the adverse effect caused by the gas jet.