Cavitation and Open-Water Performance of a Set of Tandem Propellers.
NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA MD SHIP PERFORMANCE DEPT
Pagination or Media Count:
Cavitation tunnel and open-water results are presented for a set of tandem propellers at various angular spacings between blades and axial spacings between propellers. The open water results show that the tandem propeller operated at 3.5 percent higher efficiency at the design condition than the parent single 3-bladed propeller. Cavitation results indicate the aft propeller has little effect on the forward propeller, but the trailing vortex sheet of the forward propeller grossly affects the cavitation pattern on the aft blades. Face cavitation on the aft propeller is absent for all angular and axial spacing between propellers. Back cavitation occurs sooner at the inner radii for the forward propeller when compared with the parent propeller. Tip vortex inception is the only cavitation that is similar in a comparison of the aft propeller with the parent propeller.
- Marine Engineering