Investigation of cavitation over a wedge using different cavitation and turbulence models in a cross-platform study

This paper investigates cavitation over a wedge using numerical simulations for cavitation numbers ranging from σ=1.47 to 2.06 with a special emphasis on the influence of cavitation and turbulence models. A cross-platform study is conducted to investigate the influence of the mechanisms driving the cavitating flow using an in-house, compressible code and OpenFOAM. This is followed by a detailed comparison of the cavitation and turbulence models in OpenFOAM. The study focuses initially on the model's ability to simulate the sub-stages of a cavitating cycle across various cavitation numbers followed by their ability to reproduce the cavity dynamics on a localized scale using void fraction values at different stations. The results show that both solvers simulate the cavity dynamics reasonably well with minor differences. Next, a discussion is conducted on the cavitation models and the turbulence models where it is observed that while both Merkle and Schnerr-Sauer can reproduce the cavity dynamics accurately, the standard k-ω Shear Stress Transport model is able to reproduce the unsteady cavity shedding without the need for an empirical correction that is usually needed in Unsteady Reynolds-Averaged Navier–Stokes (URANS) turbulence models to predict sheet to cloud cavitation transition. Finally, it is observed that the URANS models over-predict the void fraction at higher σ numbers while the Delayed Detached Eddy Simulation model can predict the void fraction accurately. Thus, this study reveals how current modeling strategies can predict the cavity dynamics observed in experiments, both on a global and a localized scale.