【作者】 徐林春；

【导师】 赵明登； 童汉毅；

【作者基本信息】 武汉大学 ， 水力学及河流动力学， 2004， 硕士

【摘要】 随着计算机技术的飞速发展，人们在研究河流泥沙问题时，越来越多的采用了数学模型，研究对象也由一维问题逐步发展到二维以及三维问题。水沙数学模型以其方便高效、费用低廉的特性，已经成为研究河道水沙运动规律和河床演变过程的一种重要手段之一。随着国民经济的发展，更多的江河水力资源得到了开发利用，对水沙数学模型也提出了新的要求，同时也为水沙运动基本理论研究的发展提供了一个很好的机遇和条件，以便水沙模型能够更好的服务于生产实践。本文在二维水沙数学模型计算方法的改进以及计算结果的可视化等方面做了一些工作，以期对生产实践和工程决策有所帮助。 本文共分六章，各章主要内容如下： 第一章为引言。首先对国内外水沙数学模型和主要数值计算方法的研究现状、河流水沙数值模拟的发展方向、目前存在的主要技术难点作了较系统的阐述，在此基础上结合水利工程的实际需要提出了本文的主要工作内容。 第二章为正交贴体坐标变换与网格生成技术。针对天然河道岸线曲折和流动区域不规则的特点，采用正交贴体坐标变换技术，对比不同控制函数和边界处理方式以优选网格生成模式，将不规则的物理区域转化到规则的计算区域，生成空间三维和平面二维内的曲线网格，使岸线与计算网格边界重合。并且通过射线扫描寻址的方法完成初始地形到计算地形的映射。 第三章为水沙数学模型及其求解方法。建立了正交贴体曲线坐标系下平面二维水沙数学模型，为避免使用交错网格，推导出了能够在正常网格下求解的一般曲线坐标系中的水位控制方程，在同位网格下采用高性能的有限分析方法求解全套水沙方程(水位控制方程、水流运动方程、泥沙输移方程)，实现控制方程的同精度算法。同时，对模拟计算中的几个关键问题提出了相应的处理方法，如采用“冻结”法和虚拟水深来处理河道动边界问题等。 第四章为数学模型的验证及其应用。将本文所建模型应用于长江武汉河段汉口边滩附近的边滩整治及防洪综合治理工程研究中，在该河段河床演变分析的基础上，结合实测水沙资料，对模型进行验证分析，并利用该模型对不同工程方案进行比选，提出相应的推荐方案，为相关决策提供参考依据。 第五章为数学模型的可视化研究。寻求数学模型计算结果新的表现方式，以MicrosoftWindowsXP和VisualBasic6.O为支撑平台，进行水流、泥沙数值模拟结果的可视化研究，采用拉格朗日方法直观再现河床冲淤变形和水流运动变化过程，实现计算过程的实时监测，更好的把握流动的基本规律。 第六章为结论与展望。对本文工作进行总结并对今后的工作进行展望。更多还原

【Abstract】 With the rapid development of the computer technology, the mathematical model is adopted more and more when it comes to the sediment study in the river. The research domain now has expanded from one-dimension research to two-dimension, even three-dimension research. The water and sediment mathematical model has become an important method when studying the movement law of water & sediment and evolution process in the river due to its characteristics of convenience, high effectiveness and low cost. At the same time, with the development of national economy, waterpower resource has been exploited and utilized further. Higher demand has been claimed to the water and sediment mathematical model. And it is a good chance for the development of fundamental research of water and sediment in order to serve the production practice preferably. So improvements to the mathematical model and new expression manner to the computational process and results have been done in the thesis in the hope of benefit to engineering decision-making.This dissertation includes 6 chapters, and the details are as follows:In chapter 1, the research actuality, main numerical computational methods, the development trend and the major technique difficulty in the water & sediment mathematical model at home and abroad are generally introduced. The main job in the thesis is presented following above content.In chapter 2, aiming at the sinuous and irregular boundary in the natural river, the curvilinear grid in two dimension and three dimension is generated adopted the technique of orthogonal body-fitted coordinate transform to adapt the regular calculating region to the irregular physical region. By comparing the mesh quality among different governing functions and boundary-deal modes, the best mesh generation mode is chosen. And the mapped from initial terrain to the calculating terrain is attained by method of radial scanning and addressing.In chapter 3, a plane 2-D water & sediment mathematical model for unsteady flow is established under the body-fitted coordinate system. The stage equation in curvilinear coordinate system that can be solved with finite analysis method(FAM) based on co-located grid is deduced. Then the whole numerical governing equations solved under the same accuracy arithmetic withFAM are attained. At the same time, measures to some key difficulties during the numerical simulation are put forward.In chapter 4, the established mathematical model above is applied to the study on shoal improvement and flood control comprehensive treatment in the reach in Wuhan of Yangtze River. Based on the analysis alluvial process, the mathematical model is verified by the measured data. The optimized scheme is recommended through the model at last.In chapter 5, the visualization technology of mathematical model is discussed based on Microsoft Windows XP and VisualBasic6.0. The alluvial process and the flow movement can be seen vividly and intuitionisticly on the screen by Lagrange method.In chapter 6, the whole work in the thesis is summed up and further research work is prospected.I apologize for what I have done. I done don’t know that is so serious更多还原