可回转双桨船舶的等效舵效模型

摘要

常规船舶通过操舵获得舵效来控制船舶航向，而对于可回转双桨船舶，由于桨⁃舵合一，船舶的回转运动依靠双桨的回转或双桨的推力差所产生的舵效完成。针对这种取消了常规舵的可回转双桨的船舶运动，根据船舶分离型运动建模方法，建立了可回转双桨船舶的运动方程及其在船舶纵荡、横荡和艏摇3个自由度上的作用力；通过分析船舶常规舵受力情况，并与可回转双桨船舶回转力进行比较，提出可回转双桨船舶等效舵效的概念，导出了可回转双桨作用下的船舶等效舵效模型。对可回转双桨船舶在此等效舵模型下的运动状态进行了数值仿真，对比了不同舵效下船舶运动的差异，验证了可回转双桨船舶等效舵效模型的有效性。%Conventionally, the course of traditional ships is controlled by a rudder, but because of the combined propeller and rudder system in rotatable twin⁃propeller ships, their turning motion is accomplished by a rudder effect generated by the rotary or thrust difference of the twin propeller. In this study, using a separate motion model for ships without a traditional rudder, we analyzed motion equations and interaction forces for three degrees of free⁃dom, including the surging, swaying, and yawing of a rotatable twin⁃propeller ship. After analyzing the force of a traditional rudder, we compared it with the rotary force of the rotatable twin⁃propeller ship. Herein, we propose the equivalent rudder concept and establish an equivalent rudder model for the rotatable twin⁃propeller ship. We per⁃form numerical simulations of the ship motion, compare differences under various rudder effects, and validate the effectiveness of the proposed model of the equivalent rudder effect for the rotatable twin⁃propeller ship.