Experimental Study on the Wind Flow and Airborne Pollutants Dispersion Characteristics in the Coastal Complex Terrains (III)

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Project title

Code/計畫編號

NSC99-2221-E019-050

Translated Name/計畫中文名

海岸複雜地形之風場及廢氣污染物傳輸延散特性實驗分析(III)

Project Coordinator/計畫主持人

Bao-Shi Shiau

Funding Organization/主管機關

National Science and Technology Council

Department/Unit

Department of Harbor and River Engineering

Website

https://www.grb.gov.tw/search/planDetail?id=2152212

Year

2010

Start date/計畫起

01-08-2010

Expected Completion/計畫迄

01-07-2011

Bugetid/研究經費

1243千元

ResearchField/研究領域

土木水利工程

"我國海岸地形有些為丘陵類型，屬於複雜地形(complex terrain)，例如基隆地區之協和火力電廠、台北深澳火力電廠等位置所在之海岸區域皆屬於丘陵地形。受複雜地形之影響，使得風場紊流變化並造成污染擴散改變。因此對於海岸複雜地形區域之風場與污染近遠域延散特性之瞭解與掌握，將有助於提供該等人口稠密之海岸區域城市與農漁業區環境污染預警之參考。本計畫擬就海岸地區複雜地形之風場與廢氣污染延散特性，進行模擬試驗與分析研究。實驗研究結果將可獲得對於在海岸複雜地形之廢氣污染物排放之擴散影響與特性，有助於該類污染物造成之海岸環境污染災害風險評估研擬之參考。本計畫為三年期，並以實驗方式逐年進行研究分析，探討海岸地區紊流邊界層作用下，海岸複雜地形(不同緩坡角度與連續地形)之風場運動力學參數與廢氣污染延散特性。已經完成第一年期，探討海岸地區緩坡地形不同斜坡角度之風場運動力學參數與紊流特性，包括有平均風速、紊流強度、雷諾應力、紊流頻譜等。另外也分析探討海岸緩坡地形不同斜坡角度之風場變化特徵與紊流統計特性參數，並分析獲得坡頂處之風場增速與地形斜坡角度之關係式。目前正進行第二年進度，量測在海岸地區緩坡地形不同斜坡角度之污染濃度場擴散，包括受到地形不同斜坡角度與紊流對擴散效應、沿煙流中心軸線之濃度垂直剖面與橫向剖面，據以獲得單一緩坡地形之變化影響污染延散之效應。本計畫將繼續進行第三年進度，主要工作內容與項目係量測分析連續地形之風場運動力學參數與污染濃度延散特性。包括連續兩個地形之不同間距變化狀況下，沿地形下游之風場分佈，以及排放源高度及離第一個地形距離之變化對於濃度場之影響效應。據此而獲致海岸連續地形分佈間距對於風場與紊流特性及污染延散特性之效應。" "Some coastal areas in our country are categorized as complex terrains. The accidents of continuous discharge of air pollutants from the chimneys of the power plants in these coastal areas may occur. As the gas pollutants discharge continuously, it may cause severe air pollution in the near urban region or agricultural region. Therefore, it is necessary to understand and predict the wind flow and air pollutants dispersion characteristics in the coastal region. The purpose of the present project is to study experimentally in the wind tunnel on the wind flow and air pollutants dispersion in coastal complex terrain. Results can be provided to assess the air environment for the coastal city or agricultural region in Taiwan. This is a three years experimental project. The experiments will be carried out in the environmental wind tunnel to investigate the wind flow kinematics and airborne pollutants dispersion in the coastal region of complex terrain. The first year of the project had finished. The wind flow kinematics and turbulence characteristics (including mean velocity, turbulence intensity, Reynolds stress, and turbulent velocity power spectrum) for the turbulent boundary layer flow past over the topography with different upwind slopes are measured and analyzed. Results of the wind flow kinematics along the upwind slope of the terrain are obtained, and the relation of wind speed-up with the slope angle at the tip of the terrain slope has acquired. The second year of the project succeeding the first year’s experiment is undergoing to investigate the pollution dispersion for upwind slope terrain. The third year proposal will be continued to conduct for investigating the flow and dispersion characteristics as the wind flows over the two terrain models arranged in tandem with different gaps. The variations for height of emission source stack and its location distance prior to the first terrain model affecting the discharge dispersion will also be studied in the third year project."

Keyword(s)

紊流邊界層
擴散
風洞
延散參數
turbulent boundary layer
diffusion
wind tunnel
dispersion parameter

DSpace CRIS

Experimental Study on the Wind Flow and Airborne Pollutants Dispersion Characteristics in the Coastal Complex Terrains (III)

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