Investigation into the flow characteristics of supercavities and comparison of the incoming flow method and the overset mesh method

• Study of supercavities using the overset mesh method and the incoming flow method. • Both approaches effectively capture the flow characteristics of supercavities. • The internal flow structures of supercavity can be categorized into three typical regions. • The re-entrant jet leakage mode exhibits a higher level of complexity and unsteadiness. The study aims to establish a simulation method for the forward motion of supercavities around underwater vehicles, laying the foundation for investigating the flow characteristics of supercavities under complex motion conditions. Two methods, namely the overset mesh method and the incoming flow method, are employed to simulate supercavities. In the overset mesh method, the fluid remains stationary, and the model follows the overset mesh region to move forward. Conversely, the incoming flow method keeps the overset mesh region stationary while the fluid attains velocity. Both approaches effectively capture the flow characteristics of supercavities, encompassing geometric shapes, gas leakage modes, and internal flow structures. These simulations demonstrate a commendable agreement with experimental results. Moreover, it is observed that the re-entrant jet leakage mode exhibits a higher level of complexity and unsteadiness in comparison to the twin-vortex tube leakage mode. The internal flow structures of the supercavity can be categorized into three typical regions: the reverse region, the boundary layer region, and the ventilation influence region. These findings contribute valuable insights into understanding and predicting the behavior of supercavities under various motion conditions.