Experimental Study on the Flow and Dispersion Characteristics of near and Far Fields for Two Pollution Sources Discharging in the Turbulent Boundary Layer (I)(Ii)

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簡歷

基本資料

Project title

Code/計畫編號

NSC100-2221-E019-016

Translated Name/計畫中文名

紊流邊界層流作用下雙點源污染排放近域及遠域之流場與擴散特性實驗研究(I)(II)

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=2347243

Year

2011

Start date/計畫起

01-08-2011

Expected Completion/計畫迄

01-07-2012

Bugetid/研究經費

531千元

ResearchField/研究領域

海洋科學
環境科學

"我國海岸地區諸多發電廠與重工業區，例如：基隆協和火力電廠、台北深澳火力電廠、台中火力電廠、高雄興達火力電廠、雲林麥寮石化工業區等，各廠或各區均有許多煙囪排放源。單一煙囪排放源基本上可視為連續點源排放，並形成單一羽昇流(plume)。在廠區常見兩支煙囪鄰近設置，當鄰近之兩支煙囪排放，造成該二羽昇流交互作用後合而為一，使得羽昇流之流場特性與紊流產生變化，同時交互作用後之羽昇流使得污染濃度擴散分布尺度改變，因此與單純單一點源排放後之羽昇流污染擴散特性有差異。為了提供雙點源排放鄰近人口稠密之海岸區域城市或農漁業區環境污染評估與排放設計操作是否符合國家相關環境保護法規規範，對於鄰近之兩支煙囪排放後之羽昇流相互作用，以及受下游地區地形影響之流場變化與污染擴散近域(near field)及遠域(far field)變化特性，有需要進行研究分析與探討。本研究計畫擬就在海岸地區紊流邊界層內雙點源污染排放羽昇流近域及遠域之流場與擴散特性進行實驗與分析研究。實驗與分析研究結果預期將可提供雙源污染排放交互作用之流場與擴散變化特性，且有助於海岸地區環境空氣污染災害風險評估研擬之參考。本計畫為二年期，並以風洞實驗方式分年進行研究分析，探討雙點源污染排放羽昇流在海岸地區紊流邊界層下之近域以及遠域之風場運動力學參數與廢氣污染擴散特性。第一年期研究，模擬海岸地區中性紊流邊界層流，當做邊界條件之迫近流場，並設計等排放強度雙點源，量測雙點源形成之羽昇流近域混合之流場變化。經由量測結果分析探討不同條件，包括雙點源排放強度(密度福祿數)、雙點源排列之間距、雙點源排列與迫近流場之角度等因素對於雙點源形成之羽昇流之運動力學參數與紊流特性之影響變化，包括有平均風速、紊流強度、雷諾應力、紊流頻譜、羽昇流中心軌跡(平均高度)、以及羽昇流捲增速度等。第二年期研究，量測雙點源形成之羽昇流在紊流邊界層內雙點源污染排放於下游為都市或鄉村地形之遠域之濃度延散實驗探討，包括雙點源排放強度(密度福祿數)、雙點源排列之間距、雙點源排列與迫近流場之角度、以及下游地形種類等對於遠域擴散影響效應，以及沿下風距離之濃度垂直向剖面與側向剖面，據以分析獲致各種因素參數之改變對於污染羽昇流擴散尺度之影響效應。" "There are many fossil power plants and heavy industry parks located beside the coastal areas in our country. For example: Shei-Ho power plant in Keelung, Taichung power plant, Kaohsiung Hsin-Da power plant, Mia-Liao petroleum chemicals industry park in Yu-Lin county. It is often encountered in these areas that two chimneys are arranged closely. The flow and dispersion behavior of two plumes for such two chimneys is different from that of the traditional plume emitted from one chimney. When the accidents of continuous discharge of air pollutants from two chimneys in these coastal areas of power plant or petroleum chemicals industry park occurred, it may caused 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 for such discharging of two chimneys from such coastal region. The purpose of the present project is to study experimentally in the wind tunnel on the flow and dispersion characteristics of near and far field for two pollution sources discharging in the turbulent boundary layer. Results can be provided as the assessment on the environmental impact on urban city or agricultural region nearby the coastal areas of power plant or petroleum chemicals industry parks in Taiwan. This is a two years experimental project to study the flow and dispersion characteristics in near field and far field for two plumes and their mutual interaction. In the first year, the project will be scheduled to measure the flow kinematics for two plumes mutual interaction in the near field, such as the mean flow velocity, turbulence intensity, Reynolds stress, integral length scale of the plumes. The plume averaged height as functions of downstream distance, gap of two sources, and discharging Froude number will also be investigated. In the second year, measurement on the far field characteristics of flow and dispersion of the two plumes interaction will be executed. The downstream of urban or country terrain types affects the far field dispersion characteristics will be mainly investigated. The other parameters such as the gap of two sources, discharging conditions (i.e. Froude number), and wind flow attack angles on the line between two sources are also the main targets of investigation."

Keyword(s)

近域
遠域
羽昇流
捲增速度
擴散尺度
紊流邊界層
near filed
far field
plume
entrainment velocity
dispersion
turbulent boundary layer

DSpace CRIS

Experimental Study on the Flow and Dispersion Characteristics of near and Far Fields for Two Pollution Sources Discharging in the Turbulent Boundary Layer (I)(Ii)

基本資料

Description