Computational investigation of cavitating flow on 3D NACA4412 hydrofoil with arc dimple

Abstract

Cavitation is an unsteady and complicated process. When the cavity develops at the leading edge of hydrofoil, it expands to the trailing edge. As cavitation travels downstream, a cloud or supercavitation phenomenon may take place, which makes the flow to be more unstable. In this study, the influence of the cavitation number on the performance of a NACA 4412 hydrofoil with a dimple at an angle of attack of 12° has been explored. The simulation has been carried out in commercial software ANSYS Fluent. Zwart Gerber-Belamri (ZGB) cavitation model along with Realizable κ-∊ turbulence model has been utilised for the computation. It has been observed that performance parameters of hydrofoils are associated with cavitation number. For an angle of attack of 120 moving from the supercavitation zone (σ = 0.3) to the sheet cavitation zone (σ = 2.5), the increase in cavitation number results in a decrease in vapor cavity volume.