3D Study of Cloud Cavitation on a Circular Leading-Edge Hydrofoil Using RANS Approaches

In spite of the improvements in computational fluid dynamics (CFD) techniques, engineering problems still need robust models that can ensure accuracy at low cost in the prediction of complex phenomena such as cavitating turbulent flows. In the present study, cavitation over a circular leading-edge hydrofoil imitating the leading-edge geometry of centrifugal pump impeller blades was analyzed for different cavitation numbers ranging from 2 to 2.7 and Reynolds numbers of 1.3 × 106 and 1.6 × 106. The unsteady simulations were conducted by using the RANS method with the Zwart-Gerber-Belamri (ZGB) cavitation model. To capture the features of cavitating turbulent flow, three turbulence models i.e. the MSST PANS, k-ε FBDCM and k-ω FBDCM were evaluated to determine the suitable turbulence model for simulating cloud cavitation over a hydrofoil. The numerical results were compared with the experimental data obtained by Bohm and the sequence of images recorded by Dular. The results showed that the MSST PANS can reproduce better the cavitation phenomenon than the k-ε FBDCM and k-ω FBDCM turbulence models when the shedding frequency and the cavitating structures were analyzed and compared with the experiment.