Comparative Analysis of Cavitation Characteristics around a Hemispherical Head-form Body using PANS and RANS Models

This study investigates cavitation phenomena around a hemispherical head-form body using the Reynolds-averaged Navier-Stokes (RANS) and partially-averaged Navier-Stokes (PANS) turbulence models within the OpenFOAM framework. OpenFOAM, an open-source computational fluid dynamics (CFD) toolbox, provides robust solvers and libraries for simulating complex fluid flows and turbulence phenomena. Numerical simulations were performed using three different grid resolutions—coarse, medium, and fine—to assess the influence of grid refinement on the predictive accuracy of the turbulence models. The analysis focuses on comparing the models’ performance in predicting pressure distributions, cavitation regions, and turbulence characteristics across varying grid densities. As an intermediate approach between RANS and direct numerical simulation (DNS), the PANS model exhibits an enhanced ability to capture detailed flow structures and turbulence interactions within cavitation regions. The results indicate that the PANS model offers more accurate predictions of cavitation behavior, particularly in resolving re-entrant jet dynamics and cavitation detachment processes, compared to the RANS model. This comparative study underscores the significance of turbulence modeling and grid resolution in cavitation simulations and establishes the PANS model as a reliable tool for analyzing complex fluid-structure interactions.