Replacing fixed pitch propellers for ship energy saving

Significant propulsive efficiency improvements can be achieved by modifying the propulsive system of a vessel. Here we discuss the impact of changes to the propeller’s diameter,number of blades,rate of revolutions and de- sign point. We also consider the application of a nozzle,especially the HR nozzle,and other energy saving de- vices to the ship hull. The proposed modifications are definitely worth investigating when considering propeller replacement.