基于FLUENT模拟的泥石流堵河流态分析
摘 要
由于全球气候环境的急剧变化以及地质活动进入活跃期，我国西部山区泥石流灾害的发生频率升高，规模变大。泥石流堵塞大河事件增多。并且泥石流堵河造成的上游淹没灾害，异岸冲刷灾害，下游洪水灾害等灾害链效应造成的经济损失远远大于泥石流灾害本身。泥石流堵塞主河引起主河水流流态的变化成为造成灾害的主要分析目标。
本文利用流体力学软件对泥石流堵河问题进行数值模拟，主要的研究内容如下：
利用ANSYS模块下的ICEM-CFD软件建立泥石流堵河模型，分别建立堵塞系数R=0.3,0.5,0.6,0.7,0.8和0.9的堵河模型，并对模型进行合理的网格划分；考虑到泥石流堵河问题的湍流特性，结合流体运动所遵循的三大守恒定律，在使用计算流体力学软件FLUENT进行后处理时采用标准的k-ε两方程模型对泥石流堵河问题进行数值模拟，通过FLUENT的可视化结果得到堵河点过流断面上主河的流态及速度分布情况。
与已开展的西南交通大学泥石流堵河室内水槽模型实验中的数据进行对比，分析数值模拟方法和实验方法所测得的流动速度随堵河系数变化的异同点及原因，验证计算机模型对泥石流堵河问题的数值模拟是否可行。
最后结合国内外学者对泥石流堵河问题的已有研究，对泥石流堵河相关灾害的防治工作提出合理的建议。
关键词：泥石流堵河，堵塞系数，ICEM CFD ，FLUENT，流场流速
BASED ON FLUENT SOFTWARE TO SIMULATE
THE FLOW ANALYSIS OF DEBRIS FLOW BLOCKING THE RIVER
ABSTRACT
Due to the dramatic change of global climate environment and geological activity into active period,the frequency and scale of debris flow disasters have increased in Chain western mountains. The events of debris flow blocked large river increased gradually. And the disaster chain effects caused by debris flow blocking the river ,such as the upstream flood disaster ,the shore erosion disaster and the downstream flooding ,which caused economic loss is much large than the debris flow itself. The changes of the main river flow state caused by the debris flow blocked the main river become a target for the main analysis of disaster.
In this paper, using fluid mechanics software numerical simulate the problems of the debris flow blocking the large river. The main research contents are as follows:
The ICEM-CFD software in ANSYS modules is used to set up the models of the debris flow blocking the river. Setting up the blocking river modle coefficient is 0.3, 0.5, 0.6, 0.7, 0.8 and 0.9. Meshing the model with a reasonable way. The turbulence properties of plugging river are into consideration. Combining the fluid movements need to follow the law of conservation of the three. The standard k-ε two equation model is used when we do the postprocess of the debris flow numerical simulation of blocking problem of the river. Through the visual results obtained the velocity distribution and flow regime of the river in cross section of the main river.
Then,comparing the results of numerical simulation with the experimental data obtained by Southwest JiaoTong University, analyzing the differences and the course of the change with two methods, by which identify the rationality of the numerical simulation.
Finally combining with domestic and foreign scholar research on debris flow blocking the river problems existing, putting forward reasonable suggestions to the disaster prevention and control work.
KEY WORDS: Debris flow blocking, Obstructive coefficient, ICEM-CFD, FLUENT, Flow velocity
目 录
第1章 绪 论 1
§1.1 研究背景 1
§1.2 研究现状 3
§1.3 研究意义 5
§1.4 研究内容 5
第2章 软件及求解介绍 7
§2.1 CFD简介 7
§2.2 ICEM CFD软件简介 7
§2.3 建模及网格划分过程简介 8
§2.3.1 数值模型概化 9
§2.3.2 创建几何模型 9
§2.3.3 定义网格参数 13
§2.3.4 生成网格 14
§2.3.5 导出网格 14
§2.4 FLUENT软件介绍 15
§2.5 FLUEN的求解过程 15
§2.5.1求解参数设置 15
§2.5.2初始化和求解计算 16
§2.6 结果分析 16
第3章 泥石流堵河数值模拟结果分析 17
§3.1数值模拟结果 17
§3.2数值模拟结果分析 24
第4章 西南交通大学泥石流堵河室内水槽实验 26
§4.1 实验简介 26
§4.2 实验装置 27
§4.3 实验结果与模拟结果对比分析 27
第5章 泥石流堵河的减灾对策 31
§5.1 泥石流堵河的成灾模式 31
§5.2 泥石流堵河的减灾对策 33
第6章 总结与展望 37
§6.1 全文工作总结 37
§6.2 未来工作展望 37
参考文献 39
致 谢 41
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