Finnish ship design and engineering specialist Foreship Ltd. has developed a new type of central skeg for cruise ships and ferries. It says its Foreship Efficiency Skeg (FES) will provide approximately 2 percent reduction in propulsion power requirements compared to a good typical central skeg shape.
The diagrams present surface velocity and velocity vectors on the surface of a typical good design and FES.
The development and verification is based on the full scale RANSE-CFD simulations (CFD stands for Computational Fluid Dynamics and RANSE for Reynolds Averaged Navier-Stokes Equations), including the effect of propulsion. The FES is applicable both for conventional shaft lines and podded propulsion. Conversion projects are also possible, as a FES can be prefabricated to enable fast installation.
The FES can be applied to both newbuilds and existing ships. In existing ships, only part of the skeg ahead of the trailing edge will be replaced by the new shape. The improvement compared with the existing skeg shape can be verified by RANSE-CFD and no model tests are needed.
July 7, 2011