限宽水域中船舶平面运动机构试验及水动力导数数值模拟

Numerical Simulation of Planar Motion Mechanism Test and Hydrodynamic Derivatives of a Ship in Laterally Restricted Water

为探究有限宽度水域中大型船舶的水动力特性,基于计算流体力学(CFD)技术对限宽水域中的平面运动机构(PMM)试验进行数值模拟.在对有限水域宽度的PMM试验的动态模拟上,开发了混合动网格技术,数值计算结果与循环水槽PMM试验结果对比证明采用该方法有效.继而模拟不同宽度水域中的PMM试验,分析船舶水动力随运动速度变化的关系.结果表明,限宽水域中水动力随运动速度变化的非线性特征更为显著,船舶操纵加速度导数增大,位置导数减小,旋转导数的绝对值有所增加,二阶非线性导数值变化较大.

To investigate the hydrodynamic characteristics of a large ship in laterally restricted water,this paper simulated the PMM test based on the computational fluid dynamics（CFD）technique.In order to realize the dynamic simulation of the planar motion mechanism（PMM）test limited by water width,a hybrid dynamic mesh technique was proposed.The proposed method was validated by comparing the numerical results with results of the PMM test in a circulating water channel.The PMM tests for different widths were simulated to analyze the relationship between hydrodynamic forces and motional velocities.The results show that the nonlinear feature of hydrodynamic forces becomes more remarkable in laterally restricted waters.The acceleration derivatives increase whereas the damping derivatives decrease,and a slight increment appears in the absolute values of rotational derivatives.The second order derivatives change drastically.