Study on motions of a sailing boat

帆船的研究工作有着悠久的历史，但它们只是基于优秀水手和设计师的经验。其中一个例外是美洲杯的研究。即使是这项研究也只是关于稳定的航行性能。本研究针对帆船竞赛及远洋航行中重要的航向及纵摇等非定常性能进行研究。主要研究成果如下：1.建立了考虑横倾非对称船体水动力作用的四自由度运动数学模型，并以此为基础研制了船舶航向模拟器; 2.利用真实的海试验船的运动记录，建立了数学模型中主要非定常水动力系数的辨识方法; 3.研制了试验船运动测量系统在真实的海上进行了试验，并进行了较准确的测量。4.重新安排了盆地内波浪、风和水流的风向，以进行无线电控制帆船模型的自由航行试验。由于入射波的船的速度降低进行了测量。在风洞中进行了帆的强迫俯仰试验。测量了玻璃钢夹层结构的附加质量、阻尼系数和升力折减，并与基于二维振动翼理论的新发展的板条理论进行了比较，同时对玻璃钢夹层结构进行了有限元分析，以获得轻质、刚性和强度高的船体。部分结构，以确认理论的适用性，以及获得实际的生产诀窍。

Research works on sailing boats have a long history, but they are only empirical based on experiences of good sailors and designers. One of the exception is research for America's cup. Even that research is just on steady sailing performance. This research is on unsteady performance such as tacking and pitching, which are crucial for yacht races and ocean cruise. The following results are obtained.1.We developed the tacking simulator based on a mathematical model of four degrees of freedom of motion considering hydrodynamic forces acting on the heeled asymmetrical hull.2.We developed the identification method of the main unsteady hydrodynamic force coefficients of the mathematical model utilizing the recorded motion of the boat tested in real sea.3.We developed the measuring system of the boat motion tested in real sea, and measured it in good accuracy.4.The direction of the wind fun of the basin with wave, wind and current was rearranged in order to carry out free running tests of a radio controled sailing boat model. Speed reduction of the boat due to incident waves was measured. The mechanism of the speed reduction was investigated.5.Forced pitching tests of the sail were carried out in the wind tunnel. Added masses, damping coefficients and lift reduction were measured, and compared with newly developed strip theory based on 2-D oscillating wing theory.Furthermore FRP sandwich structures were analyzed by FEM in order to obtain light, rigid and strong hulls. Partial structures were made to confirm the applicability of the theory as well as to obtain practical production know-how.