The Automatic Self-Propulsion Test System at Mitsui's Akishima Laboratory

Abstract

Self-propulsion tests are frequently carried out to estimate the required power of ships. However, it's very difficult to settle the propeller revolution speed at a self-propulsion condition, because to control a model ship on a constant towing force is troublesome. A new self-propulsion system which can be automatically controlled by feedback mechanism was developed by the Akishima Laboratory of Mitsui Engineering and Shipbuilding Co., Ltd. In this system a model ship is towed by a self-balancing resistance dynamometer. Then, the propeller revolution speed is controlled through an electrical feedback loop connected with the resistance dynamometer, which measures the difference between the actual thrust and the identical model ship resistance at the self-propulsion point. This paper shows the outline of this automatic self-propulsion system, and also describes several results of simulation study by an analogue computer and actual model experiments by using this system.