【作者】 陈珺；

【导师】 谈广鸣； 张小峰；

【作者基本信息】 武汉大学 ， 水力学及河流动力学， 2005， 硕士

【摘要】 蓄滞洪区与堤防、水库等共同组成防洪工程体系,在我国抗洪、防洪事业中具有及其重要的地位。随着计算机技术的发展,利用数值模拟技术模拟蓄滞洪区分蓄洪水时的水流演进过程,是一种极其有效的手段。国内外许多学者应用平面二维水流数学模型,对蓄滞洪区水流演进过程进行模拟。本文在总结前人研究成果的基础上,在研究蓄滞洪区水流数值模拟技术上进行了探讨,取得了以下进展:(1)介绍一种已有的蓄滞洪区二维水流数学模型,并将该模型应用于实际工程;(2)针对蓄滞洪区存在河渠的复杂地形条件,对已有的蓄滞洪区二维水流数学模型进行拓展;(3)针对笛卡尔坐标方法处理复杂边界存在的锯齿状问题,引进斜对角笛卡尔方法,对已有的蓄滞洪区二维水流数学模型进行了改进;(4)对蓄滞洪区分洪口门的数值模拟进行了探讨,建立了一种模拟分洪口门展宽及刷深的数学模型。 本文共分为6个部分,主要内容如下: 笫一部分为引言,明确地说明了本文研究的对象和目的。对平面二维水沙数学模型的研究现状和存在的重要技术问题、主要数值计算方法作了较系统的阐述,在此基础上提出了本文拟开展的主要工作。 第二部分采用已有的蓄滞洪区二维水流数学模型模拟东西湖蓄滞洪区洪水演进过程,并对拟建的穿越该蓄滞洪区的高速公路工程和高压输电线路工程进行了防洪影响评价。 第三部分在蓄滞洪区存在河渠的复杂地形情况下,根据洪水在河渠外区域和河渠内运动特点的不同,对已有的蓄滞洪区二维水流数学模型进行拓展,建立了相应的数学模型。该模型计算时能考虑河渠有、无堤防两种情况,更能符合实际情况。 第四部分针对笛卡尔坐标方法处理复杂边界存在的锯齿状问题,引进斜对角笛卡尔方法,对已有的蓄滞洪区二维水流数学模型进行了改进。通过检验,该模型能更好模拟复杂边界处水流运动规律,拟合精度较高。最后将改进后的模型运用到龙骨湖、沉底湖蓄滞洪区实际计算中,取得了较好结果。 第五部分对蓄滞洪区分洪口门的数值模拟进行了探讨。通过对分洪口门展宽更多还原

【Abstract】 The system of flood control projects consist of flood detention areas, dikes, reservoirs, etc. The flood detention areas play an important role in flood control in china. With the development of computer technology, it is an effective method to simulate the process of flood propagation in food detention areas by the numerical simulation. The horizontal 2-D flow mathematic model has been used to simulate the process of flood propagation in food detention areas by many scholars around the world. Based on the previous achievements, this paper studies method of numerical simulation in the flood detention areas, and some improvements was obtained: (1) The 2-D flow mathematic model in the flood detention area has been introduced and applied to practical projects. (2) Considering the existing of rivers in flood detention areas, the paper has improved the former 2-D flow mathematic model. (3) Aiming at the dentate boundary problem which is brought by the traditional Cartesian method, the paper employs the diagonal Cartesian method to improve the former 2-D flow mathematic model. (4) The paper discusses the numerical simulation of opening in the flood detention area, and builds a mathematic model to simulate the widening and scouring process of opening.There are 6 parts in this paper, they are arranged as follows:Part 1 is the introduction, it gives the object and the aim of study in the paper. The present situation, the main problems and numerical methods of the horizontal 2-D flow and sediment mathematic model are formulated systematically. Based on these, the main work of the paper is put forward.The 2-D flow mathematic model in the flood detention area is applied to the flood detention area of the DongXi Lake in Part 2. Considering the two situations of the freeway project and the high-tension transmission line project running through the flood detention area, the paper appraises the effects of the two projects in the flood detention area.Part 3 improves the former 2-D flow mathematic model and sets up a new one, which considers the situation of the barrel-drain existing in flood detention areas and the different hydraulic characteristics of flood between the barrel-drain field and out of the barrel-drain. The new mathematic model can be used for the barrel-drain with embankment or not. It agrees with the fact better.Aiming at the dentate boundary problem which is brought by the traditional Cartesian method, Part 4 introduces the diagonal Cartesian method to improve the former 2-D flow mathematic model. Comparison of simulated results shows that the improved model can give more reasonable flow characteristic. Finally, it is applied to the flood detention area of the Longgu Lake and Chendi Lake, and obtains satisfactory results.Part 5 studies the simulating method of the opening in the flood detention area. It divides the opening’s widening and scouring process into four continuous parts: bed scouring, lateral erosion, dike failure and amending the bed configuration. Applied to general model, the new mathematic model is reasonable to simulate the opening’s widening and scouring process.Part 6 sums up the whole paper and prospects further research work in the future.更多还原