本文選題：街道峽谷 + 污染物擴(kuò)散　； 參考：《山東建筑大學(xué)》2015年碩士論文

【摘要】：隨著我國工業(yè)化和城市化進(jìn)程的加快,近年來城市機(jī)動車數(shù)量迅速增長,機(jī)動車排放的污染物已成為城市大氣污染的主要來源。城市化過程中為節(jié)約土地資源,城市建設(shè)主要選擇高層建筑,高層建筑的增多形成很多街道峽谷,其對城市環(huán)境的影響也越來越大,致使機(jī)動車排放的大量有害氣體難以擴(kuò)散出去,積聚在街道峽谷內(nèi),使居民日常出行暴露在高濃度機(jī)動車尾氣污染物中,同時(shí)對臨街建筑室內(nèi)空氣質(zhì)量將產(chǎn)生嚴(yán)重影響,嚴(yán)重危及城市居民的身心健康。因此對城市街道機(jī)動車排放污染物擴(kuò)散規(guī)律以及對建筑室內(nèi)外空氣質(zhì)量的影響進(jìn)行全面研究具有非常重要的現(xiàn)實(shí)意義。本文結(jié)合大氣環(huán)境、交通規(guī)劃、流體力學(xué)、數(shù)值分析以及城市規(guī)劃、建筑設(shè)計(jì)等學(xué)科知識,使用數(shù)值模擬和風(fēng)洞實(shí)驗(yàn)相結(jié)合的方法研究了城市街道峽谷機(jī)動車排放污染物的擴(kuò)散規(guī)律和分布情況,為城市街道的合理布局與城市街道的規(guī)劃建設(shè)提供科學(xué)的依據(jù),對改善城市居民生活質(zhì)量,實(shí)現(xiàn)城市和交通的可持續(xù)發(fā)展具有重要意義。本文的研究對象為三條平行的街道峽谷,實(shí)際中對應(yīng)的是濟(jì)南市三條平行的道路,解放東路、和平路和文化東路。研究工況為來流垂直于街道峽谷長度方向時(shí),四個(gè)不同風(fēng)速下的街道峽谷內(nèi)氣體流速分布特征和污染物濃度分布特征,以及五個(gè)不同風(fēng)向下,孤立型街道峽谷內(nèi)氣體流場特征,還模擬了污染源強(qiáng)的變化和兩側(cè)建筑物高度不同對氣體擴(kuò)散的影響,根據(jù)流場特征總結(jié)出街道峽谷內(nèi)污染物擴(kuò)散規(guī)律。本文采用數(shù)值模擬計(jì)算,風(fēng)洞實(shí)驗(yàn)進(jìn)一步驗(yàn)證的方法,比較客觀地總結(jié)出街道峽谷內(nèi)污染物擴(kuò)散的情況和濃度場分布的特點(diǎn)。全面分析了街道峽谷內(nèi)污染物擴(kuò)散的影響因素,包括污染源強(qiáng)度及其與建筑物的距離、風(fēng)速、風(fēng)向、風(fēng)速和風(fēng)向協(xié)同作用、街道峽谷的類型、太陽輻射、人行走廊等因素。建立了城市街道峽谷內(nèi)污染物傳輸擴(kuò)散的數(shù)學(xué)模型,包括控制流體流動的連續(xù)性方程、動量方程、K-ξ雙方程以及污染物擴(kuò)散方程。對街道峽谷內(nèi)氣體流場和污染物濃度分布先進(jìn)行數(shù)值模擬計(jì)算,將數(shù)值與風(fēng)洞實(shí)驗(yàn)測量的結(jié)果進(jìn)行校對,從而驗(yàn)證了數(shù)值模擬的準(zhǔn)確性。通過對街道峽谷內(nèi)污染物傳輸擴(kuò)散規(guī)律的數(shù)值模擬結(jié)果的分析,揭示了當(dāng)來流垂直于街道長度方向時(shí),無論街道中有無障礙物,都會在街道峽谷中形成一個(gè)順時(shí)針的旋渦,這個(gè)旋渦將污染物帶至背風(fēng)側(cè),這樣一來,背風(fēng)側(cè)污染物濃度就會高于迎風(fēng)側(cè)。越靠近下風(fēng)向,街道峽谷背風(fēng)側(cè)污染物濃度越高,迎風(fēng)側(cè)污染物濃度也較上風(fēng)向的兩個(gè)街道峽谷迎風(fēng)側(cè)高。隨著風(fēng)速增大,街道峽谷內(nèi)部背風(fēng)側(cè)和迎風(fēng)側(cè)污染物濃度逐漸減小,但背風(fēng)側(cè)污染物濃度始終高于迎風(fēng)側(cè)。同時(shí),也模擬了風(fēng)向、污染源強(qiáng)、兩側(cè)建筑物相對高度對街道峽谷內(nèi)污染物擴(kuò)散的影響。搭建了街道峽谷內(nèi)部流場測量的實(shí)驗(yàn)臺,將粒子圖像測速(PIV)技術(shù)應(yīng)用于風(fēng)洞實(shí)驗(yàn),對街道峽谷內(nèi)氣體流速分布進(jìn)行測量,概括了PIV系統(tǒng)中相機(jī)光圈數(shù)、激光脈沖時(shí)間間隔以及示蹤粒子的大小對流速分布測量結(jié)果的影響。當(dāng)來流垂直街道長度方向時(shí),對街道峽谷內(nèi)部的二維流場進(jìn)行了完整測試,獲得了眾多實(shí)驗(yàn)數(shù)據(jù)。本文所作的研究為城市區(qū)域街道峽谷內(nèi)機(jī)動車排放污染物的控制、交通流量的控制、城市街道的合理布局與城市街道的規(guī)劃建設(shè),大氣污染評價(jià)、監(jiān)測與防治提供理論依據(jù)。
[Abstract]:With the accelerated process of industrialization and urbanization in China, the number of urban motor vehicles has increased rapidly in recent years. The pollutants discharged by motor vehicles have become the main source of urban air pollution. In the process of urbanization, the main choice of high rise buildings is to save land resources, and the increase of high-rise buildings has formed a lot of street canyons. The impact of the environment is becoming more and more large, resulting in a large number of harmful gases emitted by motor vehicles, which are difficult to spread out and accumulate in the street canyons. The daily travel of the residents is exposed to the high concentration of vehicle exhaust pollutants. At the same time, the indoor air quality of the street buildings will be seriously affected, which seriously endangers the physical and mental health of the urban residents. Therefore, the city is seriously endangering the physical and mental health of the urban residents. It is of great practical significance to carry out a comprehensive study on the diffusion of pollutants in urban streets and the influence of the indoor and outdoor air quality on buildings. This paper combines the knowledge of atmospheric environment, traffic planning, hydrodynamics, numerical analysis, urban planning, architectural design, and the combination of numerical simulation and wind tunnel experiments. Methods the diffusion law and distribution of vehicle emission pollutants in urban street canyons are studied. It provides a scientific basis for the rational layout of urban streets and the planning and construction of urban streets. It is of great significance to improve the living quality of urban residents and realize the sustainable development of city and traffic. The research object of this paper is three parallel. The street canyon in reality corresponds to the three parallel roads in Ji'nan, the East Road, the peace road and the East Road. The study conditions are the characteristics of gas velocity distribution and the distribution characteristics of the pollutant concentration in the street canyons under four different wind speeds, and the isolated street under five different wind directions. The characteristics of the gas flow in the channel Canyon also simulated the influence of the strong change of the pollution source and the different height of the building on the gas diffusion. According to the characteristics of the flow field, the diffusion law of the pollutant in the street canyon was summed up. The numerical simulation and the square method which was further verified by the wind tunnel experiment were used to objectively summarize the pollutants in the street canyon. A comprehensive analysis of the factors affecting the diffusion of pollutants in the street canyon, including the intensity of the pollution source and its distance from the building, the wind speed, the wind direction, the wind speed and the direction of the wind, the type of street canyons, the solar radiation, the pedestrian corridor and other factors. The pollutant transport in the city street canyon is established. The mathematical model of diffusion, including the continuity equation controlling the flow of the fluid, the momentum equation, the K- zeta double equation and the pollutant diffusion equation, is used to simulate the gas flow field and the concentration distribution of the pollutants in the street canyon, and the results of the numerical and wind tunnel experiments are proofed, thus verifying the accuracy of the numerical simulation. The analysis of the numerical simulation results of the transport and diffusion of pollutants in the street canyon reveals that when the stream is perpendicular to the street length, no matter whether there is an obstacle in the street, a clockwise clockwise vortex is formed in the street canyon, which leads the pollutant to the leeward side, thus the concentration of the contaminant on the leeward side will be high. On the windward side, the closer to the downwind direction, the higher the pollutant concentration in the leeward side of the street canyon, the concentration of the upwind side is higher than the upwind side of the two street canyons. As the wind speed increases, the concentration of the leeward side and the upwind side of the street canyon decreases gradually, but the concentration of the leeward side pollutants is always higher than that in the windward side. The influence of the wind direction, the strong pollution source, the relative height of the buildings on the pollutant diffusion in the street canyon. An experimental platform for the measurement of the flow field in the street canyon is built. The particle image velocimetry (PIV) technology is applied to the wind tunnel experiment. The gas velocity distribution in the street canyon is measured, and the number of the aperture of the camera and the laser pulse in the PIV system is summarized. The influence of the time interval and the size of the tracer particle on the measurement of the velocity distribution. When the stream is perpendicular to the street, the two-dimensional flow field in the street canyon is fully tested and a large number of experimental data have been obtained. This study is for the control of the emission of vehicles in the street canyons in the urban area and the traffic flow. Control, reasonable layout of urban streets, planning and construction of urban streets, air pollution assessment, monitoring and prevention provide theoretical basis.

【學(xué)位授予單位】：山東建筑大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X734.2

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本文編號：1843632