Advantages of a rudder bulb
24 August 2021
Did you know that a rudder bulb enables fuel savings up to 1,5% per journey?
A rudder bulb is a streamlined bulb, which is fixed at the leading edge of the rudder. It improves the water flow in front of the rudder and fills the vacuum behind the centre of the propeller. In addition, the rudder bulb reduces propeller induced cavitation, which will result in an extended lifetime of the rudder by less cavitation damage in propeller hub area.
Computational Fluid Dynamics (CFD) calculations together with tank tests have proven direct fuel savings up to 1,5% when a bulb is applied to a rudder, depending on the ship type and its steering behaviour. This energy saving device is best suited to seagoing vessels with large propeller hub sizes and high thrust loads, such as bulk carriers, container ships, oil and chemical tankers, RORO vessels and cruise ships. A bulb can be installed in new-build and existing ships (retrofit).