Study on Effect of Hull-flare Form for Sea-keeping Qualities

自1990年以来，我们一直在研究船体喇叭形状对耐波性的影响。主要结论如下：(1)建立了考虑船体张开效应的二维体水动力估算方法。研究表明，船体张开对水动力的影响较大。(2)船体张开对波浪载荷和作用于三维体上的附加波阻影响较小。船体张开对附加波阻有影响。此外，本理论还能很好地估计一阶力。然而，对于二阶力，如附加波阻和船舶周围的波型，理论计算结果与实验结果之间存在一定的差异。推导了Neumann-Kelvin问题附加波阻的验证方法。我们已经从理论上讲清楚了c…更多的计算和实验表明，新的项应该添加到Maruo的公式中。这些新项是由于穿透体表面交点产生的动量和能量通量的变化率与前进速度不一致造成的。(4)为了提高三维面元法计算三维水动力的精度，我们发展了核函数的计算方法。此外，我们还将其应用到一艘船上，以检验水动力的估计精度。通过理论计算结果与实船试验结果的比较可知，一、二次波浪力的估算精度在短距离内变差。明确了船型与耐波性之间的相互关系。在此基础上，得出了提高船舶在波浪中性能的指导方法。较少

We have studied on the effect of hull-flare form for sea-keeping qualities since 1990. The main conclusions obtained in this study are summarized as follows :(1) We have developed the estimating method for the hydrodynamic forces on 2-D body which include the hull flare effect. It has made clear that the effect of hull-flare on the hydrodynamic force is large.(2) The hull-flare effect on the wave loads and the added wave resistance acting on 3-D body is relatively small. The hull-flare affects on the added wave resistance. In addition to that, the present theory can estimate well the first order force. However, there are some discrepancies between theoretical results and the experimental ones concerning the second order forces such as the added wave resistance and wave pattern around a ship. Therefore, we should develop a new calculating method.(3) We have derived the validation method of the added wave resistance on the Neumann-Kelvin Problem. We have made clear from the theoretical c … More alculation and the experiment that the new terms should be added to Maruo's formula. The new terms are caused by the inconsistency in the changing rate of momentum and energy flux arising from the intersection on the surface-piercing body with forward speed.(4) We have developed the calculating method of the kernel function to improve the accuracy of the 3-D hydrodynamic forces due to the 3-D panel method. Furthermore, we have applied it to a ship to check the estimation accuracies of the hydrodynamic forces. It has become clear that a large number of panels on a ship are essential to improve its accuracy.(5) According to the comparisons between the theoretical results and experimental results on a full ship, the estimating accuracies of the first and second wave forces become worse in the short range. We should investigate the theory furthermore.(6) We have made clear the mutual relation between the ship hull forms and the sea-keeping qualities. Following this, we have gotten the instruction method improving the ship performance in waves. Less