Simulation of cavitation over a wedge using various cavitation and turbulence models

Cavitation occurs when the local liquid pressure drops sharply below vapor pressure, forming vapor bubbles that collapse as they exit the low-pressure region and result in noise, vibration, and erosion damage thus, being performance-degrading to hydraulic machinery. Conversely, cavitation has promising applications in geothermal energy and non-invasive surgery. The process is characterized by the cavitation number, the ratio of the difference between local pressure and vapor pressure to the dynamic pressure. Numerical modeling of cavitating flows requires coupling a cavitation model with a turbulence model to capture the cavitation-turbulence interplay accurately. This study investigates cavitation over a wedge across various cavitation numbers using different cavitation and turbulence models, emphasizing cavity shapes and localized void fraction comparisons in OpenFOAM. The study employs the Saito, Merkle, and Schnerr-Sauer cavitation models, along with k-omega Shear Stress Transport (SST) with & without the Reboud viscosity correction, Spalart-Allmaras and the Delayed Detached Eddy Simulation (DDES) models. On comparison with experimental data, results indicate that while all cavitation models predict similar cavity lengths, they differ in cavity widths at the inception point, at the wedge's top. The turbulence models show similar cavity shapes regardless of the eddy viscosity correction, highlighting challenges in simulating cavitation and turbulence model development.