MAN B&W Controllable pitch propeller. Optimizing propeller equipment. Hydrodynamic design of propeller blades
The propeller blades are computer designed, based on advanced hydrodynamic theories, practical experience and model tests at various hydrodynamic institutes.
The blades are designed specially for each hull and according to the operating conditions of the vessel.
High propulsion efficiency, suppressed noise levels and vibration behaviour are the prime design objectives.
Propeller efficiency is mainly determined by diameter and the corresponding optimum speed. To a lesser, but still important degree, the blade area, the pitch and thickness distribution also have an affect on the overall efficiency.
Blade area is selected according to requirements for minimum cavitation, noise and vibration levels.
To reduce the extent of cavitation on the blades even further, the pitch distribution is often reduced at the hub and tip.
Care must be taken not to make excessive pitch reduction which will effect the efficiency.
Thickness distribution is chosen according to the requirements of the Classification Societies for unskewed propellers.