【作者】 陈红梅；

【导师】 邹早建；

【作者基本信息】 武汉理工大学 ， 船舶与海洋结构物设计制造， 2004， 硕士

【摘要】 小水线面双体船(Small Waterplane Area Twin Hull，SWATH)船型设计的关键技术之一是其水动力性能(快速性、耐波性和操纵性)的预报和优化设计，而其静水阻力预报是其快速性预报的重要内容。和常规船型一样，预报SWATH船型的静水阻力可采用船模试验、理论和数值计算方法。随着计算机科学技术的发展及其在造船学科的日益广泛的应用，基于计算流体动力学(Computational Fluid Dynamics，CFD)技术的数值计算方法已成为预报船舶阻力和优化设计船型的有效工具。这类方法也为我们预报SWATH船型的静水阻力提供了一种有效工具。 为了尝试采用现代CFD方法数值预报SWATH船型的兴波阻力，本论文开发了一种基于非均匀有理B样条(Non-Uniform Rational B-Splines，NURBS)的高阶面元法，不但用NURBS表示物面及自由面的几何形状，而且还用其表示物面及自由面上的源强分布。NURBS的应用提高了几何及源强密度表达的精度，能够方便地满足所需的任意阶连续性的要求，不需要引入局部坐标，所以避免了局部坐标与整体坐标之间的转换。其具体做法是在物体表面和所选取的自由面上布置Rankine源来模拟厚度效应，通过满足物面边界条件、线性自由面边界条件来求解未知源强的控制网格，进而计算物体兴波波形和阻力。为了满足远前方无波的辐射条件，本论文采用了Jensen等提出的“网格错位”方法来满足，即将自由面源层上置一定高度，相应的自由面配置点向后错位一个面元纵向长度。 本文运用该方法计算了三维物体的绕流、兴波波形和兴波阻力，给出了Wigley、数学SWATH船型定常直航运动时的兴波波形和兴波阻力，其结果与实验结果、理论结果进行了比较，结果比较令人满意。 本论文的研究为用CFD方法预报SWATH船型的水动力性能打下了一定的基础，对提高我国SWATH船型的开发与设计水平具有一定的实用意义。更多还原

【Abstract】 One of the key techniques in SWATH design is the prediction and optimum design of the hydrodynamic performances (resistance and propulsion, seakeeping, maneuverability), whereas the resistance prediction is the most important task of hydrodynamic performance prediction. As with conventional ships, the methods of model experiment, theoretical analysis and numerical calculation are applied to predict the resistance of SWATH. Along with the development of computer scientific techniques and wide appliance in shipbuilding, numerical method based on CFD technique has become an effective tool for predicting the resistance and optimum design of ships.In order to predict the wave resistance of SWATH by applied CFD technique, this thesis presents a raised panel method based on NURBS for calculating flow, the wave pattern and wave resistance of a 3-D body advancing with forward speed on or beneath the free surface.In this thesis, NURBS is applied not only to represent the body geometry, disturbed free surface, but also to represent the unknown source strength distribution. This makes the geometry representation of the body shape and the wave pattern more precise. Rankine sources are distributed on panels of body surface and free surface. The source strengths are determined by satisfying the body surface boundary condition and the linearity free surface boundary condition, so that the velocity potential, the wave pattern and the wave resistance could be obtained. The radiation condition is satisfied numerically with collocation points shifting upstream.As applications of the method, flow around a 3-D body, the wave pattern and wave resistance of a ship are solved. The encouraging numerical results are achieved.This research is useful for hydrodynamic calculation of the ship by using CFD technique and for improving the techniques in prediction and optimumdesign of SWATH.更多还原