波浪中三体船非线性横摇运动近似解析解及特性分析

Approximate analytical solution and characteristic analysis of nonlinear roll motion of trimaran in waves

为了深入研究三体船横摇运动特性,本文应用多尺度法计算了波浪中非线性横摇运动的近似解析解,并通过数值方法及模型试验进行了三体船适用性验证。研究结果表明:三体船型的特殊性引起的非线性横摇阻尼和非线性恢复力使其具有特殊的横摇运动特性。其中,非线性阻尼主要影响横摇幅值变化,特殊的高阶非线性恢复力导致幅频曲线刚度渐硬,小阻尼共振状态下可能会发生不稳定大幅横摇运动。该研究从理论角度解释了三体船在波浪中可能表现出的与常规单体船不同的大幅横摇、跳跃、多值等非线性现象。

In order to further study the roll motion characteristics of trimarans,the approximate analytical solution of nonlinear roll motion equation in waves is calculated by the multiscale method,and is verified by the numerical method and model tests.The results showed that the nonlinear rolling damping and nonlinear restoring moment caused by the particularity of trimarans have special rolling motion characteristics,that nonlinear damping mainly affects the variation of rolling amplitude,that special higher-order nonlinear restoring force leads to stiffening of amplitude-frequency curve,and that the unstable and large rolling motion may occur in the case of low-damping resonance.The nonlinear phenomena such as large roll,jump and multi-value,which may be different from those of conventional single-hull ships,are explained theoretically.