摘要
该文利用边界元程序WAMIT研究了船体固定和自由浮动状态下月池共振频率的偏移,并建立了六个不同尺寸参数的船体来探究船体尺寸参数对月池共振频率偏移量的影响。月池形状为矩形。在不同频率的规则波中,计算得到固定和自由浮动状态下月池内自由液面升高、船体垂荡和纵摇随入射波频率变化的曲线。把自由液面随入射波频率变化曲线上的局部最大极值点视为共振发生处。文章系统地比较和分析了固定和自由浮动状态下的共振频率,同时还对船体运动响应曲线和波面升高响应曲线之间的关系进行了比较。结果表明,固定状态下的共振频率或多或少要比自由浮动状态下的共振频率小。船体吃水的增加会减小共振频率的相对偏移量。月池长度的增加会增大共振频率的相对偏移量。月池内台阶长度的增加会明显减小活塞式共振频率的相对偏移量,但是会增加晃荡式共振频率的相对偏移量。此外,还发现月池共振会给船体垂荡和纵摇运动带来明显影响。
The differences in moonpool resonance frequencies between fixed and free-floating conditions are studied using the radiation-diffraction code WAMIT. Six vessel models with rectangular moonpools are built with different hull parameters to examine how the vessel configuration affects the shift of moonpool resonance frequencies. In regular waves with different frequencies, free surface elevation in moonpool, the heave and pitch motions with respect to incident wave frequencies are computed for both fixed and free-floating conditions. The resonance frequencies are obtained by searching for the local maximum points in frequency-elevation curves. The resonance frequencies between fixed and free-floating conditions are compared and analyzed systematically. The free motion RAOs and the free surface elevation in moonpool are also examined together. It is found that the resonance frequencies in fixed condition are more or less smaller than that in free-floating condition. The increase of vessel draft will reduce the relative difference of resonance frequencies. The increase of moonpool length will enhance the relative difference of resonance frequencies. The increase of recess in moonpool will reduce the relative difference in piston mode distinctly, while it will enhance the relative difference in sloshing modes. Moreover, it is revealed that the moonpool resonances can affect the heave motion and pitch motion dramatically.
作者
黄海洋
许新
张新曙
尤云祥
HUANG Hai-yang;XU Xin;ZHANG Xin-shu;YOU Yun-xiang(State Key Laboratory of Ocean Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration,Shanghai 200240,China)
出处
《水动力学研究与进展（A辑）》
CSCD
北大核心
2019年第4期482-488,共7页
Chinese Journal of Hydrodynamics
基金
国家自然科学基金（51679138）~~
关键词
月池
共振
自由浮动
moonpool
resonance
free-floating
