Dynamics of unsteady cavitating flow in compressible two-phase fluid

• Development of an implicit pressure-based algorithm for the computation of unsteady compressible cavitating flow.
• Implementation of the algorithm in the open-source program, OpenFOAM.
• Computations of both partial and super cavitating flows over cylinders.
• Study of the unsteady feature of pressure waves in cavitating flows.

A pressure-based compressible-medium numerical method is developed and applied to the computation of cavitating flow. The cavitating flow is regarded as a homogeneous mixture with the density of the mixture being a function of the void volume fraction. The void volume fraction is governed by a transfer equation, in which the finite phase change rate is considered. To include the compressibility effect, the equation of state of each phase is introduced into the numerical modeling. The governing equations are solved using a pressure–velocity coupling approach, where finally an implicit pressure correction equation is obtained and solved. Our calculation demonstrates that the present compressible-medium numerical method is capable of simulating the dynamics of unsteady cavitating flow. In addition, this method is applicable to the study of the wave propagation in the flow fields, such as waves induced by the collapse of the cavitation cloud, or the presence of imposed external pressure waves.