淹没垂直圆柱横摇问题的解析研究

Analytical solutions of radiation problem by a submerged cylinder

应用匹配特征函数展开法建立了有限水深淹没垂直圆柱横摇问题的解析解,通过与边界元方法的对比验证了该方法的正确性。基于上述模型,对淹没圆柱水动力系数进行了研究,结果表明,在大多数频率下,淹没圆柱的附加质量总是大于同样大小的漂浮圆柱,且在高频段近似为漂浮圆柱附加质量的两倍。当淹没深度较大时,圆柱附加质量趋向于常数,辐射阻尼趋向于零。当水深较浅时,淹没圆柱附加质量随着水深的增加而减小,辐射阻尼受水深的影响则始终不显著。

By means of the eigen-function expansion-matching method,an analytical solution was developed for pitch problem by a submerged vertical cylinder in finite water depth.It was validated by comparison with the result from a boundary method.Numerical examinations show that added mass of submerged cylinder is larger than that of the floating cylinder.It seems to have a twice relationship at high frequency range.If submerged deeply,added mass tends to a constant,and radiation damping approaches to zero.Added mass decreases with the increase of water depth,but radiation damping has no evident effect by water depth.