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耀斑形式对船舶耐海性能的影响。主要结论如下：(1)建立了考虑船体耀斑效应的二维船体水动力估计方法。结果表明，船体耀斑对水动力的影响较大。(2)船体耀斑对波浪载荷和附加波浪阻力的影响相对较小。船体耀斑对附加波浪阻力有影响。除此之外，本理论还能很好地估计一阶力。然而，对于船周围附加波阻力和波浪型等二阶力，理论结果与实验结果存在一定的差异。因此，我们应该开发一种新的计算方法。(3)推导了Neumann-Kelvin问题中附加波阻的验证方法。通过理论计算和实验表明，Maruo公式中应该加入新的项。新项是由于穿面体与前进速度相交产生的动量和能量通量变化率不一致造成的。(4)利用三维面板法，提出了核函数的计算方法，提高了三维水动力计算的精度。最后，将该方法应用于船舶，验证了其水动力估计的准确性。很明显，船上大量的面板对于提高其精度是必不可少的。(5)理论计算结果与全船实验结果对比表明，在较短的范围内，第一波力和第二波力的估计精度变差。我们应该进一步研究这一理论。(6)阐明了船型与耐海性之间的相互关系。在此基础上，提出了提高船舶波浪性能的指导方法。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