A Panel Method for Trans-Cavitating Marine Propellers

The extension to super-cavitating propellers of the numerical panel method developed by the Marine CFD Group of the University of Genova is presented and largely validated in the paper. The validation of the theoretical model for the cavity detachment and closure in the wake of the blade profiles is presented first on a typical super-cavitating profile for which theoretical and experimental solutions are known. Then the 3D panel method is applied on the complete series of Newton-Rader trans-cavitating propeller for which experimental measurements in cavitation tunnel and numerical results obtained by other researchers have been recently published. The main dynamic characteristics such as thrust and torque coefficients versus the advance ratio and the cavitation index, but also the cavitation patterns, in terms of bubble length at various radii, bubble volume and extension on the trailing vortex wake are presented and discussed for various propellers of the N-R series, having different pitch and expanded area ratios. Good correlations are in general achieved for what regards not only cavitation patterns, but also thrust and torque breakdown consequent to the cavity inception and growth on propeller blades