复杂水系整体二维水动力模拟研究

发布时间：2018-03-09 16:20

本文选题：浅水方程　切入点：复杂水系　出处：《清华大学》2014年硕士论文　论文类型：学位论文

【摘要】：自然界中的水系多为不同类型水域连通的复杂系统，如河流-湖泊水系、河流-海湾水系、水库-渠道水系等。由于不同水域的地形特性和不同模型适用性的差异，常常需要几种模型进行分区-耦合模拟，，如一、二维耦合模拟。耦合模拟常存在交界面附近的数值精度降低、计算失稳等问题，为此，本文提出并开发了一种适用于多地形区域的整体水动力模拟的平面二维模型。论文在比较分析一维模型和平面二维模型优缺点的基础上，提出在平面二维模型中考虑网格单元内地形变化的思路；从水流连续性和动量守恒原理出发，引入了水位系数、等效水深和等效水力半径等概念，推导了考虑单元内地形变化的控制方程。论文利用OpenFOAM开发平台，实现了控制方程的离散和求解；提出了一种在单元内布点的方法，有效模拟了单元内地形的变化，并得到水位系数、等效水深和等效水力半径等随水深变化的映射关系，建立了InnerParts2D水动力模拟模型。 InnerParts2D模型首先应用于传统的一维问题模拟。分别使用虚拟梯形河道恒定均匀流和实际三亚河网感潮流算例进行了模型验证；通过与多种模型、多种模拟方案的对比，说明了InnerParts2D能较精确地模拟传统的一维问题。在此基础上，论文将InnerParts2D模型应用到了三亚海湾-河流系统，实现了对不同类型水域组成的（传统研究一般需要采用一、二维耦合模拟技术的）复杂水系的整体二维水动力模拟。在该算例中，也针对若干典型二维单元开展了新引入变量的过程分析，以此说明了InnerParts2D模型在模拟中对地形数据的使用情况和对传统二维模型的改进情况。论文研究表明，由于地形精度的提高，InnerParts2D的模拟精度明显优于传统的二维模型，而运行速度的降低并不明显，为采用粗网格模拟地形变化较大的水域提供了可能。而且，InnerParts2D可以自然地应用于河网的模拟，使河流-湖泊-近海等复杂水系的整体模拟成为可能。InnerParts2D模型的建立为大区域、复杂水系的整体模拟提供了有力的工具。
[Abstract]:In nature, water systems are complex systems connected by different types of water bodies, such as fluvial and lake systems, fluvial and gulf systems, reservior-canal systems, etc. Due to the differences in topographic characteristics and applicability of different models in different water areas, Several kinds of models are often needed for partition-coupling simulation, such as one and two dimensional coupling simulation. Coupling simulation often has problems such as low numerical accuracy near the interface and unstable calculation. In this paper, a planar two-dimensional model for hydrodynamic simulation in multi-terrain regions is proposed and developed. On the basis of comparing and analyzing the advantages and disadvantages of one dimensional model and two dimensional plane model, this paper puts forward the idea of considering the topographic change in the grid element in the plane two dimensional model, and introduces the water level coefficient from the principle of water flow continuity and momentum conservation. Based on the concepts of equivalent water depth and equivalent hydraulic radius, the governing equation considering the topographic variation in the unit is derived. In this paper, the discretization and solution of the control equation are realized by using the OpenFOAM development platform, and a method of arranging points in the unit is proposed. The mapping relationships of water level coefficient, equivalent water depth and equivalent hydraulic radius with the variation of water depth are obtained, and the InnerParts2D hydrodynamic simulation model is established. The InnerParts2D model is first applied to the traditional one-dimensional problem simulation. The model is verified by using the virtual trapezoid river steady uniform flow and the actual Sanya river network, and compared with various models and simulation schemes. It is shown that InnerParts2D can accurately simulate the traditional one-dimensional problem. On this basis, the InnerParts2D model is applied to the Sanya gulf-river system. The whole two-dimensional hydrodynamic simulation of complex water system is carried out. In this example, the process analysis of new introduced variables is also carried out for some typical two-dimensional elements. The use of terrain data in the simulation of InnerParts2D model and the improvement of the traditional two-dimensional model are illustrated. The research shows that the simulation accuracy of InnerParts2D is better than that of the traditional 2D model because of the improvement of terrain precision, but the decrease of running speed is not obvious. And InnerParts2D can be applied to the simulation of river network naturally, which makes it possible for the whole simulation of complex river system, such as fluvial, lake and offshore, to establish the InnerParts2D model in a large area. The overall simulation of complex water systems provides a powerful tool.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV131.2

【参考文献】