A CFD study made it possible to visualize the wave profile around a Wigley hull and to calculate the resistance. The purpose of this study is to develop a new propulsive system for ships, inspired by the tail fin of a fish. Expected advantages are lower underwater noise, better maneuverability at low ship speeds and higher efficiency. The typical motion for good propulsive performance is a combination of heaving and pitching.
Both CFD and experiments are used to optimize the artificial fin. Below you can see the mechanism that drives the fin. It consists of a reversed crank-rod mechanism for the heaving motion and a spring mounting for the pitching motion, i.e. the pitching happens passively under the influence of the hydrodynamic forces. This excludes the need for a second actuator, and allows the foil to adapt to vortices in the water. The efficiency of this swimming machine reach high values. Below, you can see the efficiency contours for a surface piercing, oscillating foil, for a range of heave frequencies and spring pretensions.
Global Budget and timing
? million euro over ? years
Joris Mattheijssens, Researcher