【作者】 詹成胜；

【导师】 邹早建； 郑伟涛；

【作者基本信息】 武汉理工大学 ， 船舶与海洋结构物设计制造， 2005， 博士

【摘要】 船舶阻力性能是舰船的基本水动力性能之一。船舶阻力主要包括粘性阻力和兴波阻力,其中兴波阻力对船型的改变相当敏感,适当修改船体型线,有可能使兴波阻力明显降低。因此,用理论、试验和数值计算的方法探讨兴波问题的机理,预报船舶的兴波阻力,并以此为基础设计阻力性能最优的船型,一直是船舶水动力学研究的热点之一。 相对于理论和试验方法,用数值的方法计算船舶水动力具有其独特的优点和发展潜力。上世纪60年代至今,随着计算机科学技术的发展,计算流体动力学(CFD)取得了重大的进展。计算流体动力学(CFD)应用于船舶水动力学问题的数值求解,产生了船舶CFD方法。在近二十多年内,世界各造船先进国家的船舶科技工作者投入了大量的力量开展船舶CFD研究,取得了巨大的成就。特别是在兴波问题的研究中船舶CFD取得了显著的成功。 近年来,非定常问题受到了较大的关注。用时域的方法描述船舶在波浪上的运动,包括线性自由面条件下的大幅振荡运动,发表了大量的文献;对于非定常兴波问题,也有一部分学者在研究。近十年来,在高速船型的开发热潮中,出现了一些新的非定常兴波问题,包括高速船启动过程的非定常兴波问题,这些问题是现代高速船舶或常规船舶在非常规条件下运动所遇到的,有些尚未得到足够的重视和研究,其机理尚有待于弄清。因此非定常兴波问题值得船舶科技工作者们进一步关注。事实上,随着船舶CFD技术的发展,求解非定常兴波问题将是船舶CFD势流方法的主要研究方向之一。 随着船舶CFD技术被越来越广泛地应用于实际工程问题,势流法求解船舶水动力学问题的快捷性和精确性越来越重要,应用高阶面元法求解船舶水动力问题成为当今的一个研究热点。近年来,出现了众多的高阶面元法,其中基于非均匀有理B样条(NURBS)的高阶面元法因为可以和船舶计算机辅助设计(CAD)更好地结合,可以更方便、快捷地进行船型设计和船舶水动力性能设计、优化,更多还原

【Abstract】 Resistance performance is one of the fundamental hydrodynamic performances of ships. Ship resistance is composed of viscous resistance and wave-making resistance, whereas wave-making resistance is sensitive to the changing of the ship shape. The wave-making resistance can be remarkably reduced by properly amending the ship form. Therefore, to design the optimal ship form by investigating the mechanism of the wave-making phenomena and predicting the ship wave-making resistance is the focus of ship hydrodynamics at all times.Compared with the theoretical and experimental methods, numerical method has some merits in predicting ship hydrodynamic performances. Since 1960’s, with the development of computer technology, many breakthroughs have been obtained on the Computational Fluid Dynamics (CFD). CFD being applied in resolving ship hydrodynamic problems results in a new branch in ship hydrodynamics - ship CFD. During the last 20 years, a great deal of efforts has been devoted to ship CFD research and great success has been achieved in this aspect. The most remarkable success of CFD in ship hydrodynamics is the numerical solution of wave-making problems.In the recent years, more and more attention has been paid to unsteady problems. There are large numbers of literatures describing the study of ship motion in waves, including the large amplitude oscillation motion with linearized free surface boundary condition. There are also some researches on unsteady wave-making problems. During the recent 10 years, some new unsteady wave-making problems appeared when developing high speed ships, including the unsteady wave-making of a high speed craft in the starting phase. These problems are encountered by modern high speed ships or conventional ships moving at unusual conditions. The mechanism of these unsteady wave-making phenomena is far from being understood. Therefore, it is necessary for researchers to pay more attention to unsteady wave-making problems. In fact, associated with the development of ship CFD, solving the unsteady wave-making problems will be one of the important research subjects of ship CFD.As ship CFD is more and more widely used in engineering problems, accurately and rapidly solution of ship hydrodynamic problems by potential theory method becomes more and more important. One of the focuses of recent researches is to solve the ship hydrodynamic problems using high-order panel method. In recent years, many high-order panel methods have been proposed, among them the high-orderpanel method based on the Non-uniform Rational B-splines (NURBS) is most promising due to its special merits that it can be combined with the Computer Aided Design (CAD) to be conveniently used in design of the optimal ship shape from the point of view of ship hydrodynamic performances.This thesis deals with the numerical solution of linearized unsteady wave-making problems in time domain. A time-domain Kelvin source high-order panel method based on NURBS is developed and applied to solve the unsteady wave-making problems caused by a ship moves forward with non-uniform speed.In Chapter 2, the mathematical formulation of the unsteady wave-making problems is described. The source distribution model of the Kelvin source panel method applied to solve the unsteady wave-making problems in a time-marching procedure is presented. Since rapid and accurate calculation of the time-domain Green function is essential to the time-marching procedure, in Chapter 3 a new method for calculating the time-domain Green function and it’s derivatives is proposed based on the work of other researchers. The results presented in this chapter have shown the efficiency of the method.In Chapter 4, some fundamental theories and technologies about NURBS which will be adopted in the subsequent calculation are introduced. Adopting the format of NURBS some curves and surfaces of ship hull are generated. The vertexes generating these curves and surfaces are directly used by the subsequent numerical calculation, which avoids the miscellaneous work of data inputting and proc更多还原