A proposal of ship gas-turbine driven waterjet propulsion - preliminary considerations

In the paper are presented preliminary considerations concerning the efficiency of water- jet ship propulsion system, as well as the calculation of main dimensions of waterjet channel.The friction and momentum losses of the flow channel have been roughly estimated by using Fliegner's equations. An important conclusion is confirmed that the summary losses are inversely proportional to square of ship velocity (~1/u2). On the other hand the ship propulsion power is directly proportional to third power of ship velocity (~u3). Therefore to minimize ship's hull resistance, hulls of waterjet-driven ships ought to be of a great slenderness - e.g. L/B =15, stabilized by sponsons, or of semi-swath hydrofoil-supported construction.