Abstract
At the stage of initial design, the manoeuvrability of ship is usually predicted by MMG model in Japan. The MMG model contains three interaction factors (1-t_R, a_H, x_H) which are determined by the rudder angle test. This paper proposes a method to calculate these factors hydrodynamically. We represent a ship hull and a rudder by SQCM (Source and QCM) and do a propeller by the simplified propeller theory. As to rudder model, we check the usefulness of the simplified rudder model which uses the center-plane source and vortex distributions. Instead of actual ship models SR-221 A, B, for simplicity, we adopt a simple strut having a parabolic water plane, and obtain the three factors through numerical calculations. Then we show the usefulness of this method comparing with the experimental results on SR-221 A, B models.
