Effect of Tip Skew Coupled Rake on Hydrodynamic Performance of Kappel Propellers

To explore the effect of tip skew coupled rake on the hydrodynamic performance of Kappel propellers, the fourth-order B-spline method was used to design and change the radial distribution of Kappel propellers in the skew and rake, and an 8-type propeller was constructed. The SST k-ω+γ transition turbulence model, where k denotes the turbulent kinetic energy, ω the specific dissipation rate, and γ the intermittency factor, was employed for simulation, with the Kap509 propeller serving to validate the accuracy of the simulation. The numerical results of the propeller’s open water efficiency are 1.06% to 2.50% lower than the experimental data. It is found that in the vicinity of J=0.8, except for conventional end-plate propellers, the efficiency of the Kap01 series propellers is consistently higher than that of the Kap02 series, with an average increase of 3%. This effect is most pronounced when the skew is 24°, where the efficiency rises by 4.78%. The propeller efficiency increases with the increase of skew when J=0.9-1.0. Under low rake radial distribution, the skew of the propeller can be appropriately improved, which can strengthen the end-plate effect of the Kappel propeller, thereby improving the propulsion performance of the Kappel propeller.