Numerical analysis of hydrofoil ventilated cavitation under wave impact

Abstract

Unsteady ventilated cavitation of a hydrofoil is analyzed with coupling of the perturbed steady two-dimensional incompressible flow of water out of the cavity and the compressible one-dimensional air flow within the cavity. The air flux from cavity at its oscillating tail and along its side boundary with the water is taken into account. The employed equations include air mass conservation law and pressure constancy condition along the cavity in both media. On the cavity boundary, however, the impermeability condition is considered from the water side and the differential momentum equation from the air side. The developed model of ventilated cavitation has been verified with the already published [1] measurements of hydrodynamic loads and their pulsations on the low-drag partially cavitating hydrofoil OK-2003A satisfactory agreement of the computed results with experimental data was manifested. Influence of the wavelength variations and air compressibility on lift and its pulsations were analyzed.