Experimental Study of the Harbor Ship Chimney Pollution Discharge Affecting on Nearby Urban Pedestrian Level Wind and Canopy Flow Environment and Pollution Dispersion Characteristics

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基本資料

Project title

Code/計畫編號

MOST106-2221-E019-035

Translated Name/計畫中文名

海域港區船舶煙囪排放對鄰近市區近地風場及頂部流與污染擴散影響實驗探討

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=12230359

Year

2017

Start date/計畫起

01-08-2017

Expected Completion/計畫迄

01-07-2018

Bugetid/研究經費

748千元

ResearchField/研究領域

土木水利工程

"台灣許多重要港口(例如基隆港、高雄港)都與市區緊鄰，港區船舶進出頻繁，航運繁重，船舶煙囪排放，廢氣污染隨著風飄移擴散之鄰近市區街道，造成市區空氣污染，影響並降低市區空氣品質。由於港市合一，因此港區船舶煙囪廢氣排放後在鄰近市區之擴散特性研究，將會有助於海岸港區城市空氣污染評估與管制之參考。本研究係在風洞模擬海域港區地況之大氣紊流邊界層，以該來流做為環境污染擴散邊界條件。船舶煙囪以點源浮升射流排放模擬之，並輸送往鄰近市區以建物比鄰形成之街道擴散。市區街道在橫風作用時，所形成之街谷型式，依前(上風建築)與後(下風建築) 之高低，可區分為前後等高，前低後高之上揚型，前高後低之下降型。實驗模擬點源污染排放由密度福祿數代表，來流流場則以雷諾數決定，街谷變化則採用建築物高度為特性長度參數。實驗量測不同型式街谷近地風場變化與街道周遭頂部流風場變化。污染濃度之獲得係以實驗採樣之追蹤氣體進行分析，並將量測在不同型式街谷之濃度分佈剖面配合統計解析方式，獲致污染濃度擴散之統計特性參數，包括污染團質心高度、擴散尺度、濃度浮升射流捲增速度及平均傳輸速度等。" "Many harbors in Taiwan locate beside the urban region, for example: Keelung harbor and Kaohsiung harbor). In such harbors, so many ships in the harbor, the waste air pollution discharged from chimney of ships dispersed to the streets of the nearby city. It deteriorated the air quality of the urban region. Study on the dispersion of waste air pollution from the ships will be helpful for assessment and control the harbor city air pollution regulation. In the present project, the atmospheric turbulent boundary layer of coastal harbor city terrain will be simulated in the wind tunnel which is used as the approaching flow. Pollution discharging from the ship chimney will be simulated as the point source of buoyant jet which transports along downwind stream and diffuses around the city street canyon. Under interaction with cross wind, different heights of upwind building and downwind building forming three types of street canyon used in this study which are the same height, the step-up, and step down. Experimental study will employ control of dimensionless parameters, such as densimetric Froude number, Reynolds number, and street canyon aspect ratio to investigate the pedestrian wind flow field near the ground of the street canyon and the canopy flow around the street buildings. The pollution concentration characteristics, such as the dispersion parameters, pollution averaged height as functions of the control of dimensionless parameters will also analyzed from the measured concentration filed. The pollution plume entrainment velocity and mean transport speed will be also analyzed."

Keyword(s)

街谷形狀比
紊流邊界層
雷諾數
近地風場
頂部流風場
濃度浮升射流
密度福祿數
延散尺度
canyon aspect ratio
turbulent boundary layer
Reynolds number
pedestrian wind field
canopy flow
concentration buoyant jet
densimetric Froude number
dispersion parameter

DSpace CRIS

Experimental Study of the Harbor Ship Chimney Pollution Discharge Affecting on Nearby Urban Pedestrian Level Wind and Canopy Flow Environment and Pollution Dispersion Characteristics

基本資料

Description