Shocks in cavitating flows

We present two numerical methods for simulation of compressible multiphase flows with phase transition. The first approach is a two-fluid method using sharp interface treatment and non-equilibrium mass transfer terms. This technique is applied to investigate collapsing vapor bubbles and resulting shock patterns. Depending on the bubble-wall configuration, different types of liquid jets are observed during the collapse stages of the bubbles. These results provide detailed insight into collapse processes and resulting peak loads. The second approach is a singlefluid method using local thermodynamic equilibrium assumptions. Its applicability to simulate cavitating flows is assessed on example of hydrofoil cavitation as well as for the collapse of a bubble cluster. Typical features of sheet and cloud cavitation are reproduced and the formation of shocks due to collapsing vapor regions is analyzed. In case of the investigated cluster of vapor bubbles, a collapse front propagating toward the focal point of the collapse is predicted. This process leads to an amplification of the intensity of the final collapse.