MULTI PHASE COMPUTATIONAL FLUID DYNAMICS MODELING OF CAVITATING FLOWS OVER AXISYMMETRIC HEAD-FORMS

In the present paper, partial cavitation over various head-forms was studied numerically to predict the shape of the cavity. Navier-Stokes equations in addition to an advection equation for vapor volume fraction were solved. Mass transfer between the phases was modeled by a sink term in vapor equation in the numerical analysis for different geometries in wide range of cavitation numbers. The re-entrant jet formation, which is the main cause for the cavitation cloud separation, was modeled very well with a modification of turbulent viscosity. In regions with higher vapor volume fractions (lower mixture densities) amodification of the k  turbulence model was made by artificially reducing the turbulent viscosity of mixture. Computed shapes of cavities were found to be in good agreement with those of the reported experiments. Simulation results also compared well with those obtained from analytical relations.

کلیدواژه ها:

Cavitation ، Turbulent flow ، Axisymmetric head-form