水库正堰与侧堰联合泄流的水力特性研究

发布时间：2018-03-31 07:32

本文选题：三维数值模拟　切入点：结构网格　出处：《大连理工大学》2014年硕士论文

【摘要】：近年来,洪涝灾害的频繁发生,增加了水利枢纽工程中泄洪的研究意义。不论高坝还是低坝,泄洪都是一个值得深入研究的复杂水气两相流难题,众多学者投入大量精力开发可以研究泄洪的方法。21世纪前,对泄洪的研究方法主要集中在物理模型试验上,随着近些年计算机科学技术的发展和计算流体力学理论的完善,对数值模拟方法的研究也逐渐展开。本文首先对现阶段水气两相流的研究成果进行了概述,并探讨了模拟泄水建筑物消能的意义。在此基础上叙述了广大学者对数值模拟研究的理论和方法,通过结合物理模型试验,对比两者的优点和缺点,分析其中的不足,并找出互补的方法。本文研究工作主要如下： 1.对流体动力学的基本理论进行归总叙述,总结出三大基本控制方程的通用表达形式。列举研究两相流的几种常用方法,对比几种紊流两方程模型,总结其分别适用的场合。简要叙述紊流的边界条件和模拟自由水面的方法。 2.介绍某水利枢纽工程的概况,模型试验的注意事项,模型的设计、安装以及试验方法。分析正堰和侧堰联合泄流时的水库泄流能力、压强分布、沿程水面线、水流流态等；对侧堰单独泄流时的流态进行分析。对比两种试验模型在同一库水位下时的泄流流态,得出侧堰泄流对正堰的影响。 3.介绍数值模拟过程中所用到的软件,把求解CFD软件的几种核心算法进行分类,总结这几种算法各自适应的场合。对物理模型进、出口边界的适用条件和对应参数的计算公式进行归纳。并由一个简单的算例来总结Fluent的求解流程。 4.适当简化实际工程,建立其三维可视化模型,用ICEM对其进行网格划分,选择合理的进、出口边界条件,采用三维κ-ε双方程模型,利用几何重建格式非恒定流迭代求解生成自由水面,复杂的几何边界采用非结构化网格进行处理,从库区到河道下游进行全程的水气二相流数值模拟,对比结构网格和非结构网格的精确性和易用性。用后处理软件对计算结果进行可视化分析,把计算结果与实测数据进行多方面对比,得出结论：数值模拟技术应用在实际工程的泄洪消能方面研究是可行的。
[Abstract]:In recent years, the frequent occurrence of flood and waterlogging has increased the research significance of flood discharge in water conservancy project. Whether high dam or low dam, flood discharge is a complicated water and gas two-phase flow problem worthy of further study. Many scholars put a lot of energy into the development of flood discharge methods. Before the 21st century, the research methods of flood discharge mainly focused on physical model tests, with the development of computer science and technology and the improvement of computational fluid dynamics theory in recent years. The study of numerical simulation method is also gradually developed. In this paper, the research results of water and gas two-phase flow at present are summarized, and the significance of simulating the energy dissipation of drain structures is discussed. On this basis, the theories and methods of numerical simulation are described. By combining the physical model test, the advantages and disadvantages of the two are compared, the shortcomings are analyzed, and complementary methods are found. The main work of this paper is as follows:. 1. The basic theory of hydrodynamics is summarized, and the general expression of three basic governing equations is summarized. Several common methods for studying two-phase flow are listed, and several turbulent two-equation models are compared. The boundary conditions of turbulent flow and the method of simulating free water surface are briefly described. 2.Introduces the general situation of a water conservancy project, matters needing attention in model test, design, installation and test method of the model. The discharge capacity, pressure distribution, water surface line along the course and the flow pattern of the reservoir under the combined discharge of positive Weir and Side-Weir are analyzed. The flow pattern of the side Weir under the same water level is analyzed and the influence of the side Weir discharge on the positive Weir is obtained by comparing the two test models under the same reservoir water level. 3.Introduces the software used in numerical simulation, classifies several core algorithms for solving CFD software, sums up the situation of each of these algorithms, and advances the physical model. The applicable conditions of the exit boundary and the calculation formulas of the corresponding parameters are summed up, and a simple example is used to summarize the flow of the Fluent solution. 4. Simplify the actual engineering properly, establish its 3D visualization model, mesh it with ICEM, select reasonable entry and exit boundary conditions, and adopt the three-dimensional 魏-蔚 two-equation model. The free water surface is generated by iteratively solving the unsteady flow with geometric reconstruction scheme, the complex geometric boundary is processed by unstructured mesh, and the numerical simulation of water and gas two-phase flow is carried out from the reservoir area to the downstream of the river. The accuracy and ease of use of structural and unstructured meshes are compared. The calculation results are visually analyzed with post-processing software, and the calculated results are compared with the measured data in many aspects. It is concluded that it is feasible to apply numerical simulation technology to the study of flood discharge and energy dissipation in practical engineering.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV135.2

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