Investigation of unsteady ventilated partial cavitating flow around an axisymmetric body with particular emphasis on the vortex structure

• The quasiperiodic variations in various physical quantities at different positions on the axisymmetric body under ventilated cavitation conditions were analyzed over time. • The specific factors influencing the morphology and development of cavities and vortices are investigated through the Q -criterion. • The primary influencing factors of different types of cavities and vortices were analyzed. This paper investigates the ventilated cavity phenomena of a symmetric body under specific conditions, focusing on the factors affecting the vortex structure. The ventilated cavitating flow development process is simulated with a homogeneous free surface model combined with a filter-based turbulence model. The results show the characteristics of the pressure pulse and the bubble shedding around the axisymmetric body. A quasiperiodic pressure pulse occurs at the middle of the body. In addition, three main types of vortices occur in ventilated partial cavitation: large-scale cloud vortices, U-type vortices, and small-scale vortices. Further analysis revealed that the cavities and vortex structures have similar influencing factors. The vorticity transport equation is applied to analyze the main factors influencing the vortex. The results indicate that fluid density primarily affects large-scale cloud vortices, the velocity gradient plays a dominant role in U-type vortices, and fluid angular velocity is the main influencing factor for small-scale vortices.