Simulating compressibility in cavitating flows with an incompressible mass transfer flow solver

The effect of finite mass transfer rate in combination with temporal resolution on the dynamics of caviting flows is subject of this study. It will be shown that global flow quantities exhibit convergent behaviour with respect to mass transfer rate and time step size in incompressible pressurebased simulation of cavitating flows. It is concluded that large mass transfer rates are required in combination with sufficiently small time steps to focus the local phase transition process to time intervals which are small with respect to both the time scale of the flow (Sezal 2009) and the characteristic cavity collapse time. Koukouvinis & Gavaises (2015) as well as Bhatt et al (2015) came to similar conclusions. The effect of finite mass transfer is demonstrated by numerical studies of an isolated bubble collapse and a cavitating wedge flow. It is further shown how a conventional finite mass transfer approach must be modified to achieve homogeneous equilibrium states as given by an arbitrary barotropic equation of state in the presence of advective density change.