波浪漂移力作用下的救助船操纵运动计算与仿真

Maneuvering motion calculation and simulation of rescue ship under wave drift force

针对南海救111船(NHJ111),研究其在深水短峰不规则波中的操纵性.采用统一模型思想建立3DOF非线性运动方程,利用经典方法对纵向动力学与桨、舵及黏性横流等力/力矩进行建模,使用Green函数源法进行频域求解,采用远场理论计算平均波浪漂移力,并验证了数值结果.将运动方程应用于南海救111船,计算其静水中的回转运动,将计算结果与实船试验数据对比,相对误差在8.0%以内;考虑漂移力的作用,在6级海况的深水短峰不规则波中进行回转运动的数值计算,结果表明,该模型精度较高,满足救助船模拟器对运动模拟及精度的要求,为预测大风浪中的救助船运动奠定了基础.

The maneuverability of a rescue ship NHJ111 in short-crested irregular waves in deep water was studied.3 DOF nonlinear maneuvering equations were established by using the unified model.The resistance and propulsion dynamics were modeled by classical methods as well as forces and moments of the propeller,rudder and viscous crossflow.The method of Green function source was adopted to solve the boundary value problem(BVP)in frequency domain,and the mean wave drift forces were calculated by far-field formulas along with numerical verification.After that,the equations of motion were applied to NHJ111,and the turning motion in calm water was performed.It is found that the calculated results are in good agreement with the experimental data of the real ship,and the relative error is less than 8%.Then the turning motion simulation was numerically calculated in short-crested irregular waves in the sea state 6 in consideration of drift force.Accordingly,the established model is capable of simulating ship motions in waves with good precision and can be utilized in the rescue ship simulator.It lays the foundation for predicting rescue ship motions in rough sea.