Performance of a family of surface piercing propellers

Tests on a systematic series of surface piercing propellers were analyzed to study some aspects of scaling the performance of this kind of propulsor. In particular, the influence of the Weber number, depth of immersion, and shaft rake are discussed and results for variations in these conditions are presented. Regression equations are given of the relationship between critical advance coefficient and Weber number, and of the thrust and torque coefficients at advance coefficients above the critical values. This work is the result of co-operative research on the scaling of the performance of surface piercing propellers that was jointly undertaken by the University of Genoa, University of Naples, Memorial University of Newfoundland, and the Institute for Marine Dynamics, NRC.