20110208377 | EFFICIENCY OPTIMIZING PROPELLER SPEED CONTROL FOR SHIPS - The invention relates to a method for improving the propulsion efficiency of vessels. The improvement is obtained by utilising wave induced variations in propeller inflow, i.e. the speed of water flowing towards the propeller. The wave induced water speed variation is used to calculate the propeller speed in a way so that the propeller speed is optimal with respect to the total propulsion efficiency. The optimal propeller speed is determined by solving an optimisation problem formulated as the maximization of the ratio of energy delivered by the propeller and the energy delivered to the propeller. The method may be used for vessels with one or more propellers. | 08-25-2011 |