【作者】 张杰；

【导师】 马山；

【作者基本信息】 哈尔滨工程大学 ， 船舶与海洋结构物设计制造， 2014， 硕士

【摘要】 船舶参数横摇属于船舶稳定问题,它极大的威胁着海上航运安全。根据非线性的强弱以及描述问题的复杂度不同,本文提出了三种预报参数横摇发生的理论模型。基于马修方程(Mathieu Equation)的单自由度预报模型为初级的理论模型,本论文基于该模型研究了参数共振(Parametric Resonance)背后的物理机理,为进一步开发更为复杂的船舶参数横摇预报方法提供了指导。第二种参数横摇预报模型为弱非线性方法,它直接求解3自由度的垂荡-横摇-纵摇耦合方程,在该模型中非线性主要来源于入射波浪力和静水恢复力,辐射力保持线性并用脉冲响应函数代替。尽管该模型在实际中被广泛的使用,但是其理论体系中尚有许多不合理之处,这会对运动响应有很大的影响。在本论文中,基于STF方法以及Cummins方法的频域转时域的方法被重新修正,并导出了新附加项,确保了频时转换后辐射力的一致性。另一方面,鉴于参数横摇发生时横摇幅值较大,船体湿表面变化较大,非线性明显,本文提出了预报参数横摇发生的第三种方法,该方法可以考虑由于物面形状改变导致的辐射力、绕射力的非线性,并能记及垂荡与横摇,纵摇与横摇之间的水动力耦合,在该预报模型中,入射波浪力、静水恢复力是在波浪与船体瞬时位置确定的湿表面上求得的。本文基于后两种预报模型对某集装箱船在迎浪规则波中进行了参数横摇的数值预报,并与实验值进行对比,并讨论了初始横摇角度,横摇阻尼,遭遇频率,波陡对参数横摇发展的影响。更多还原

【Abstract】 The parametric rolling is a severe stability problem of ships, which endanger the crew’s lives and our property. In the present thesis, multi-level numerical models classified by different complexity and nonlinearity are developed to evaluate this phenomenon. The 1DOF Mathieu Equation is the elementary level, which explains the mechanism of parametric resonance. The second level employs a 3DOF weakly nonlinear model, where Radiation/Diffraction forces are kept linear and represented by impulse response function,while the Froude-Krylov forces are evaluated on the instantaneously wet surface of the ship with high order Stokes wave theory. Despite of the fact that this method is commonly used in industry, there are still some improper places in the basic theory, which have great influence on motion response. In the present work,the Cummins’s method combined with STF to calculate ship motion in time domain is reconstructed and some additional terms are derived.On the other hand,a 2D simplified body-exact solver is developed to solve the nonlinear Radiation/Diffraction force, which is implemented by the third level. In this level, the Froude-Krylov forces are calculated on the instantaneously wet surface of the ship and 3DOF motion equations are solved in time domain. The last two models are employed to simulate the parametric rolling of one container ship and the numerical results are validated by experimental data. The influence of initial roll angle, roll damping, wave steepness and encounter frequency on the development of parametric rolling is discussed.更多还原