规则波中船舶操纵与垂荡、纵摇耦合运动模拟与特性分析

采用MMG分离模型的思路,在船舶六自由度操纵性运动方程中叠加波浪垂荡力和纵摇力矩,构成波浪中船舶操纵与垂荡、纵摇耦合动力学模型,用来模拟规则波中船舶操纵与垂荡、纵摇耦合运动特性。其中的波浪力由切片法计算,船舶航向保持采用PD控制模式。采用耦合动力学模型计算了某船在规则波中保持航向时的垂荡、纵摇运动,并与试验结果进行了比较。两者的幅频曲线形式上基本一致,间接证明了耦合动力学模型的有效性。进而采用该模型计算了该船在不同浪向角和航速下保持航向稳定的垂荡、纵摇运动,以垂荡、纵摇等值极坐标曲线形式表征了船舶规则波浪中操纵与垂荡、纵摇的耦合运动特性。

Simulation and Characteristics Analysis on the Coupling Motion of Heave

By uniting manoeuvring motion equations of six degrees of freedom and heave force and pitch moment of a ship in regular waves, the thesis constructed ship dynamic model, in which MMG model in calm water was adopted and heave force and pitch moment were calculated with strip method, and proportional & differential control model was used for keeping course. Based on the above model, this paper simulates the coupling motion of heave and pitch for a ship keeping course in regular waves. The calculated results had good agreement with model test on amplitude-frequency response, which indirectly proved the effectiveness of coupling dynamic model. Furthermore, with different wave angle and ship speed, the coupling motion of heave and pitch for a ship in regular waves were simulated, and the characteristics of which were obtained in the form of amplitude isoline in polar coordinates.