波浪上船体与液舱晃荡耦合的非线性时域模拟

Nonlinear time-domain simulations of ship motion coupled with tank sloshing in waves

为研究外流场非线性对船体与液舱晃荡耦合运动性能的影响,本文基于势流理论提出一种计算波浪中船体与液舱晃荡耦合的时域混杂法。该方法对外流场的入射波力和静恢复力计算考虑了波浪环境下瞬时湿表面的非线性影响;对于内部流动的液舱晃荡采用时域边界元法,将该舱液面引起的力矩进行修正,实现对规则波不同工况下耦合运动时历的求解。本文以S175为例,对规则波中迎浪与横浪情况下有无航速的载液船舶运动响应进行模拟,并与实验数据对比验证。研究表明:本方法考虑外流场非线性后,能对不同工况下的船体液舱晃荡能给出较好的模拟结果,并且相较线性方法有一定的改善,为工程应用提供快速高效的技术手段。

A hybrid time domain method based on potential flow theory was developed to calculate ship motion coupled with tank sloshing to study the effects of nonlinear external flow on the performance of the coupling motion of ships and sloshing tanks.Nonlinear effects of instantaneous wet surfaces under wave conditions were accounted for when calculating incident wave and static restoring forces.For tank sloshing,a time domain boundary element method was adopted to correct for moments caused by the liquid surface of the tank and to solve for the coupling motion of regular waves under different working conditions.We used S175 as an example to simulate the motion response of liquid-carrying ships,with or without speed,under head and beam sea conditions in regular waves,and compared the results with experimental data for verification.This method,which accounted for nonlinear cases,better simulated ship motion coupled with tank sloshing under different working conditions.Compared with linear methods,this method provides a fast and high-efficiency technical means for engineering applications.