基于阻力和伴流不均匀度的多用途船型线优化

为探究多用途船首尾型线变化对船舶水动力性能的影响,采用RBF(Radial Basis Functions)曲面变形方法分别对多用途船首尾型线进行变换,使用优化拉丁超立方法设计计算样本,引入Kriging近似模型解决传统CFD计算耗时的问题。在此基础上,以船舶的阻力性能以及桨盘面伴流不均匀度作为优化目标,利用带精英策略的非支配排序遗传算法(NSGA-Ⅱ)完成整个型线优化流程。计算结果表明,对于该多用途船,船首形状朝V型发展有利于减小兴波阻力,船尾的V型横剖面在接近推进器处逐渐向U型转变,可以在获得更均匀伴流场的同时对阻力性能影响较小。

Hull optimization of multipurpose ship based on resistance and wake non-uniformity

In order to study the influence of the variation of multipurpose vessel’s bow line and stern line on the hydrodynamic performance, RBF(Radial Basis Functions) surface deformation method was used to transform the multipurpose vessel’s lines, and the optimized Latin square method was used to design the calculation sample. The time-consuming problem of traditional CFD calculation is solved by the Kriging approximation model. On this basis, the ship’s resistance and the wave non-uniformity at the propeller disk are taken as the optimazation goals, and the fast and elitist multiobjective genetic algorithm(NSGA-II) is used to complete the whole optimization process. The calculation results show that for the multipurpose vessel,the development of the bow shape towards the V-shape is beneficial to reduce the wave resistance. The V-shaped cross-section of the stern line gradually changes to the U-shape near the propeller, which can obtain a more uniform wake field while the resistance performance is influenced slightly.