一种精细面元辐射能量的波浪增阻计算方法

Method to calculate added wave resistance based on radiation energy method with detailed ship panel

在核算现有船舶能效指数时,波浪增阻是必须被计算的一项。采用远场法计算船体波浪增阻时,船体被看作整体进行运动响应和增阻的计算,然而船舶通常较长,纵摇对首尾垂向运动影响较大,以重心处的运动来表征全船的做法不再具有适用性。同时,以船舶重心处的数据进行整体“史密斯”效应修正,忽视了船体表面各处波浪起伏和波浪动压力的不同。为此,该文在船体表面每个面元计算辐射水动力,并单独计入当地“史密斯”效应的影响,结合辐射能量法,对湿表面积分得到全船辐射增阻。通过对不同航速的集装箱船S175和KCS进行波浪增阻计算,并与切片理论及试验结果进行比较,证明了该方法的有效性与准确性。

Added wave resistance is what it must be calculated when EEXI is needed.The whole ship is regarded as a rigid body when calculating the added wave resistance with far-field method.As the length of ships is generally long,pitching has a significant effect on the motion response on fore and aft.Also,in the past the"Smith"effect correction is always based on the data at the center of gravity of the ship,which ignores the difference of wave shape fluctuations and the wave dynamic pressure on ship hull.In this paper,a method is proposed to solve this problem.Hydrodynamic coefficients and motion response are calculated and saved on each pane,and the“Smith”effect is also calculated locally on each panel.Combined with the radiation energy method and integrating along wet ship body,the added wave resistance on each panel is obtained.Through the calculation of added wave resistance for S175 container ship and KCS container ship under various conditions,the calculative results are compared with the experimental results and the STF results,which shows that this method is more accurate for the calculation of ship added wave resistance.