Sensitivity evaluation of a transport-based turbulent cavitation model

A sensitivity analysis is done for turbulent cavitating flows using a pressure-based Navier-Stokes solver coupled with a phase volume fraction transport model and non-equilibrium k-ε turbulence closure. Four modeling parameters are adopted for evaluation, namely, C_ε1 and C_ε2, which directly influences the production and dissipation of turbulence kinetic energy, and C_dest and C_prod, which regulate the evaporation and condensation of the phases. Response surface methodology along with design of experiments is used for the sensitivity studies. The difference between the computational and experimental results is used to judge the model fidelity. Under non-cavitating conditions, the best selections of C_ε1 and C_ε2, exhibit a linear combination with multiple optima. Using this information, cavitating flows around an axi-symmetric geometry with a hemispherical fore-body and the NACA66(MOD) airfoil are assessed. Analysis of the cavitating model shows that the favorable combinations of C_dest and C_prod, are inversely proportional to each other for the geometries considered. A set of cavitation numbers is selected for each of the geometries to demonstrate the predictive capability of the present modeling approach for attached, turbulent cavitating flows.