The key objective of the Energopac is to reduce the vessel’s fuel consumption by fully integrating the design of both the propeller and rudder.
Each Energopac is designed to fit the vessel and to meet its specific requirements. This allows Energopac to be fully optimized for energy efficiency, whilst not compromising either the vessel’s manoeuvrability or its comfort levels.
Energopac reduces fuel consumption by effectively reducing the flow separation behind the propeller hub. Extended studies show that for the same course-keeping capabilities, Energopac will create less drag than conventional rudder systems. Most notably, when using small – corrective – steering forces to maintain course, the difference in rudder resistance is significant. The high-lift performance of Energopac requires smaller steering angles, which consequently reduces rudder resistance.
The reduction in fuel consumption depends very much on the type of vessel, its operational profile, and on the reference propeller and rudder. Wärtsilä can estimate the actual power savings for any application.
The estimate is based on the vessel design, its operational profile, and other relevant data. Proven savings in required power for a vessel’s trial speed vary between 2–9%, thanks to Energopac.
Energopac will effectively reduce the operational costs for any vessel having a considerable degree of free sailing time in its operational profile. In addition, it will work very well for propellers with a relatively large propeller hub.
The potential savings are large for vessels with highly loaded controllable pitch propeller systems, such as RoRo-vessels, ferries, container / multipurpose vessels, and vessels with an ice class notation.
By applying Energopac, conflicting requirements can be effectively optimized. High performance propeller designs are often a compromise between increased efficiency, and reduced vibration levels.
Energopac allows for a propeller design that gives the optimal balance between these requirements.