The Study Of Atmospheric Flow Field Around Highways Road Embankment

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.