Research on the unsteady characteristics of ventilated cavitating flows in the form of gas-leakage by toroidal vortex

To understand the unsteady characteristics of ventilated cavitation in the form of gas-leakage by toroidal vortex, the ventilated cavitating flows around axisymmetric body are researched by the experimental and numerical methods. A filter-based turbulence model is used in numerical simulation in order to accurately capture the vortex separation. In experiment, the high-speed video camera is used to observe the flow structure. The results show that the numerical results are consistent with the experimental results. The unsteady ventilated cavitating flow is the shedding process of cloud bubble in the rear of ventilated cavity. Flow separation in the region of ventilated cavity is caused by adverse pressure gradient, resulting in a complex vortex structure. An interaction between vortex structure and the main flow leads to the cloud bubble shedding in the rear of ventilated cavity.