【作者】 张晓兔；

【导师】 张乐文； 刘祖源；

【作者基本信息】 武汉理工大学 ， 流体力学， 2002， 博士

【摘要】 随着我国加入WTO以及经济体制改革的深入进行，航运事业必然会得到蓬勃发展，而面对航道中日益增多的船舶，人类迫切需要了解船体上所受到的水动力情况，尤其是船体通过桥墩、两船相遇时的干扰水动力变化趋势，这些对避免船舶碰撞等海难事故的发生具有重要意义。 计算流体动力学的发展和商业化，为数值模拟船舶流场提供了条件。与试验方法相比，数值计算方法具有自身的优点与发展潜力。作者在对与船体水动力尤其是干扰水动力的研究相关的文献的阅读与分析的基础上，结合作为定义工业产品几何形状的唯一数学描述的非均匀有理B样条方法，选择B样条(统一成非均匀有理B样条形式)来进行有关三维船体水动力的数值计算研究工作。它不仅为船体水动力的研究带来了新的处理方法，而且在船舶计算机辅助设计与船舶流体动力学之间起到了无缝的接口作用。 作为数值计算的基础性工作，第2章采用人机交互的方式对船体型线与船体曲面进行几何造型，并全部统一成非均匀有理B样条形式，所生成的网格顶点直接为后续水动力的数值计算利用，这样避免了传统水动力计算程序中的许多数据输入和处理的过程。为了考查本文方法的可行性，第3章以圆球体绕流、圆柱绕流以及两个等圆球体在流场中的附加质量作为例子，通过在物体表面布置强度以非均匀有理B样条表达的源汇和着重对奇异积分的处理后完成了相应的计算，从与理论解的比较可以看出本方法的优越：在数目很少的配置点下数值解可取得十分良好的精度。第4章对Wigley船型的线性兴波阻力、不同弗氏数下的三维波形和等高线图作了数值计算，也取得了令人满意的结果。 由于有升力的存在，第5章直接从速度势格林公式出发，并采用了一种近似的Kutta条件，首次采用B样条边界元方法对作斜航船武汉理}_人学博十学位论文体的操纵水动力开展了数值计豹.训一究工作，所得到的结果在小角度斜航时精度要好于作大角度斜航时的精度，这可能因为所采纳的Kutta条件所导致的。第6和7资卡卜对船体之间的干扰水动力问题，分别从两个层次上予以研究，即进行拟定常化处理和完全在时域内作三维非定常计算，从与己公开发表的文献试验资料比较来看，所得的结果可以在定性和数量级上很好地反映干扰水动力的变化趋势，从而为了解船舶碰撞的运动机理提供了有力的理论根据，同时也为如何实避碰提供了一定的决策支持。第8章选择日本MMG的操纵运动数学模型对船舶作回转运动、Z型操纵试验的情况进行了数值模拟，并着重考虑了航道水深对船舶操纵性能的影响问题，其目的上要是为了课题组今后进一步开发诸如内河船舶操纵模拟器、船舶避碰计算机动态演示的需要。最后第9章对全文进行了总结并提出了今后进一步的研究方向更多还原

【Abstract】 The cause of shipping must have a flourish development with the access to World Trade Organization and further reformation of economy system of our country. It is imperious need to understand the hydrodynamic forces acted on ship hull while the amount of ships in the sea-routes is increasing. These forces, especially the changing tendency of hydrodynamics when the two ships are meeting or a ship is passing a pier are of great importance to avoid the shipwrecks such as ship collision.Computational Fluid Dynamics (( FD) provides a condition for numerically simulating ship fluid flow field with the development and commercialization. CFD has its superiority and potential for developing with contrast to trial method. Incorporating the non uniform rational B spline (NURBS) which is the only definition of the form of industry products, the author selects the method of B spline to do the numerical computation research work of the hydrodynamics of three dimensional ship hull based on the reading and analysis of the documents about hydrodynamics, especially the interaction hydrodynamics. The method not only brings a new method for the calculation of the hydrodynamics of ship hull, but also provides an interface effect having no sew between the ship Computer Aided Design (CAD) and ship Computational fluid Dynamics (CFD).As a fundamental work of the numerical calculation, Chapter 2 geometrically sculpts the body lines and surface of ship hull using an interactive method and adopts the format of NURBS. The vertexes are directly used by the latter numerical calculation, which avoids the tedious work of data inputting and processing in the traditional CFD programs. In order to verify the feasibility of the present method, Chapter 3 takes the fluid flow of sphere, cylinder and the additive mass of two spheres as three examples, finishes the calculation by disposing the source or sink whose strength is expressed as the format of NURBS and emphatically the processing of the singular integral. It can be drawn from the comparison of the results of present method andthe theoretical solution, i.e. a good precision can be gotten under a few collocation points with the method. Chapter 4 computes the wave-making resistance, the 3D wave figure and its contour figure of Wigley ship and makes satisfying results.Chapter 5 directly sets out from the Green formulae of velocity potential due to the existence of lifting force, adopts an approximate Kutta condition and firstly calculates the maneuvering hydrodynamics of a Wigley ship with an attack angle using the present method of B spline. The precision of the numerical results at a small attack angle is better than that at a big attack angle. It may owe to the approximate Kutta condition adopted here. Chapter 6 and 7 are divided into two parts for the interaction hydrodynamics, i.e. the quasi-steady and the unsteady calculation fully in time domain. The results qualitatively and quantitatively agree with the trial results published in the documents. These not only provide theoretical basis for the motion mechanism of ship collisions, but also give the decision support on avoiding the ship collisions.Chapter 8 simulates the ship maneuvering motion of turning and zigzag test and takes into account the effect of water depth on ship maneuverability by use of the Maneuvering Model Group (MMG) of Japan. The main aim is to satisfy the need such as developing the maneuvering simulator of freshwater, the dynamic demonstration of avoiding ship collisions. Finally, Chapter 9 summarizes the whole paper and puts forward the further research interests.更多还原