【作者】 郑超超；

【导师】 贾影；

【作者基本信息】 北京交通大学 ， 结构工程， 2012， 硕士

【摘要】 本课题属于国家自然基金项目一“高速公路建设对区域气流场影响的研究”(51178033)的一部分。高速公路的快速发展给国民经济和区域经济的发展带来了便利,促进了沿线地区的经济发展,产生了巨大的经济和社会效益。但同时也带来了一系列的环境问题,特别是大气环境污染。高速公路建成后,汽车尾气的排放、扬尘等,使得沿线地区的大气环境污染度增加,这种污染会随着高速公路运营时间的增长及交通量的增加而不断加重。所以对高速公路区域气流场的研究是非常有意义的。空气的流动即形成风。风场数值模拟技术的理论核心是流体动力学(CFD)和数值计算方法,它所依赖的控制方程在数学上为一组偏微分方程,用其描述空间中流体的流动情况。本文采用的SST k-ω湍流物理模型,是以基线模型(Baseline model, BSL模型)为基础,考虑了湍流主剪应力输运的影响,该湍流模型使预测逆压梯度的流动(分离流)方法得到重要改进。本文利用CFD通用计算软件CFX12.0作为计算平台,主要研究内容有：(1)在阅读、研究大量文献资料的基础上,从大气来流、特征湍流、风致响应等方面,深入了解高速公路周边气流场的主要研究方法和发展过程,指出高速公路周边气流场研究可能存在的问题,为下一步的研究工作奠定基础。(2)结合高速公路结构的特点,从计算域的尺寸,网格的划分,边界条件,离散格式,湍流模型的选取,收敛性及结果的判定等方面提出了数值模拟方法的建议。并且应用建议的方法对标准6m立方体实测模型进行了数值模拟验证。(3)从基本几何特性出发选取了不同路堤高度、边坡坡度的高速公路。路堤高度和边坡坡度对流场的分布有重要影响。并且研究了不同几何参数对流场的影响。(4)应用本文所提出的相关CFD数值模拟方法,给出高速公路周边流场的变化规律,为高速公路建设及区域空气环境治理提供可靠的依据。(5)对本文的研究工作进行总结,对数值模拟中的一些问题提出一些自己的看法,提出需要进一步进行的研究工作。更多还原

【Abstract】 This dissertation is a part of the National Natural Science Foundation of China (51178033) named "The research on the effect of highway construction on regional airflow field". The rapid development of highway has brought great convenience to the prosperity of national economy and regional economy, and also has promoted the economic development of the coastal areas, so it has produced great economic and social benefits. But at the same time, it also brings a series of environmental problems, especially in atmospheric environment pollution. After the highways are built, the automobile exhaust emissions and other problems will increase the atmospheric environment pollution in coastal areas. What’s more, with the growth of the highway operation time and the increase volume of traffic, the pollution will be worse and worse. Thus, it’s very significant to do research in highway area flow. The flow of the wind forms the wind. The theory core of wind load numerical simulation technology is fluid dynamics (CFD) and numerical method, and the control equation which this technology depends on is a set of partial differential equations in mathematics, by which we can describe the flow of fluid in space. This article adopts the SST k-ω turbulent physical model, which based on the baseline model and considers the influence of turbulent Lord shear stress transport. Thus, the SST k-ω turbulence model makes an important improvement to the method of predicting the adverse pressure gradient flow.This paper chooses the common CFD calculation simulation software-CFX12.0to be calculation terrace. The main research contents:(1) On the basis of reading and research a lot of literature, from the atmosphere to flow, the characteristics of turbulence, wind-induced response, in-depth understanding of the main methods and development process of flow field around highway and lay the foundation for further study.(2) Combined with the characteristics of the highway structure, from the size of the computed field, the division of the grid, the boundary conditions, discrete format, turbulence model selection, convergence and judgement of the result, this paper puts forward suggestions of numerical simulation. And application of the proposed method of numerical simulation to make confirmation about the standard6m cube measured model. (3) From the basic geometrical characteristics select different embankment height, slope of highway. Embankment height and slope has important influence on field distribution. Consider the effect of different geometric parameters of the flow field.(4) Application of the suggested of CFD numerical simulation method, this paper give the rule of flow field around highway. The study provide reliable basis for highway area air environment management.(5) Summary the research work of this article and put forward some opinions of numerical simulation and put forward further studies on the job.更多还原