IMPROVED PROPULSIVE EFFICIENCY BY WEAKING THE PROPELLER HUB VORTEX

By Peter Pospiech at June 20, 2013 05:13
Filed Under: Company News, drive systems

Weakening the propeller hub vortex behind the propeller decreases propeller resistance and manifests itself as increased thrust. The deflection of the flow aft of the propeller by the optimized profiled fins reduces the propeller torque. In addition to the improved propulsive efficiency, the new Wärtsilä EnergoProFin propeller can also be applied to reduced propeller-induced noise and vibrations. 

Wärtsilä's EnergoProFin and normal propeller in comparison

Wartsila EnergoProFin 

Fuel prices have increased considerably over the last years, making propulsion efficiency even more important than before. The energy losses of a propeller are among other things related to flow phenomena around and behind the propeller boss. Installing the new Wartsila EnergoProFin (WEPF) could increase the overall propulsion efficiency by up to 5% with a payback time of less than one year, reports the company. The result on investment period is relatively short thanks to the attractive price of this propeller. Payback times of 3-14 months are achievable. The company’s new power transmitter is a propeller cap with fins, rotating together the propeller, resulting in an average fuel oil saving of up to 5% and payback time of less than a year for seagoing vessels. 

The propeller is made from the same material as the propeller (NiAlBr) and replaces the normal propeller boss cap. The propeller is easy to install; it can even be installed when the vessel is afl oat provided the vessel can be suffi ciently trimmed. Once the new propeller type is installed, the only required maintenance is polishing during regular cleaning intervals. 

FOR ALL SHIP TYPES EQUIPPED WITH FIXED PITCH PROPELLERS. 

The Wärtsilä EnergoProFin is suitable for all new builds and existing vessels regardless of propeller make. The screw is only applicable to vessels with fixed pitch propellers. The EnergoProFin is designed as an integral part of the propeller. The installation of the new propeller will not affect the manoeuvrability of the vessel. The new screw comes with all required mounting materials and tools. Mounting of the EnergoProFin is simple and can be performed by the shipyards. The newly developed Wärtsilä product is available since end of 2012 and has been installed in April 2013 for the first time on the, under British flag running, 275.616 t ore carrier Berge Lhotse

 

graphs: courtesy of Wärtsilä

Comments are closed

Tag cloud