Multi-phase CFD analysis of natural and ventilated cavitation about submerged bodies

A multi-phase CFD method has been developed and is applied here to model the flow about submerged bodies subject to natural and ventilated cavitation. The method employs an implicit, dual-time, pre-conditioned, multi-phase Navier-Stokes algorithm and is three-dimensional, multi-block and parallel. It incorporates mixture volume and constituent volume fraction transport/generation for liquid, condensable vapor and non-condensable gas fields. Mixture momentum and turbulence scalar equations are also solved. Mass transfer modeling provides exchange between liquid and vapor phases. The model accounts for buoyancy effects and the presence/interaction of condensable and non-condensable fields. In this paper, the theoretical formulation of the method is summarized. Results are presented for steady-state and transient axisymmetric flows with natural and ventilated cavitation about several bodies. Comparisons are made with available measurements of surface pressure distribution, cavitation bubble geometry and drag coefficient. Three-dimensional results are presented for a submerged body running at several angles of attack. The underlying three-species formulation and the specific models employed for mass transfer and momentum diffusion are demonstrated to provide good correspondence with measurements; however, several weaknesses in the current modeling are identified and discussed.