臺灣博碩士論文加值系統

本研究主要是利用大氣環境風洞實驗探討都市地形下，在不同高度與間距下兩排建築物形成之上升型街谷汙染水平排放擴散之變化。
實驗分析獲致以下結果：
(1) 利用臺灣海洋大學環境風洞實驗室配合渦流產生器及粗糙元素模擬出所需之
都市地形紊流邊界層，且指數律風速剖面之n值為0.27，符合Counihan(1975)實場調查研究結果之建議值。
(2) 汙染物自前排建物以水平方式排放時，街谷內的濃度會因街谷之間距有所不同，而有不同程度的累積，且因後排建物高度的影響造成在街谷內的濃度聚集於不同區域。
(3) 於街谷間濃度擴散尺度的變化與位於前排建物之高度變化成正比。
(4) 在水平向之濃度擴散分佈量測之實驗值結果符合高斯擴散理論之公式。

This study was to explore the dispersion characteristics of elevated point source discharging horizontally into step up street canyons. Experimental results are summerized as:
(1)Spries and roughness elements are used to simulate a turbulent boundary layer flow which is expressed power law profoile with an exponent of 0.27. This value is found to within the range of urban type of atmospheric boundary layer flow proposed by Counihan(1975)
(2)As the pollutant was discharging horizontally into the canyon,accumulation of pollutants occurred in different regions for changing the canyon width.The windward side of step up canyon has found pollution accumulation when the windward side building height increases.
(3)The dispersion parameters variations are proportional to the elevated source heights which is located in the leeward side of step up canyon.
(4)The measurd horizontal concentration distributions are found to close to the prediction of Gaussian diffusion equation.

摘要 I
ABSTRACT II
目次 III
圖次 V
符號說明 IX
第一章 導論 1
1-1前言 1
1-2研究目的 1
1-3文獻回顧 1
第二章　風洞試驗之基本理論分析 3
2-1中性大氣紊流邊界層之風場特性 3
2-2中性大氣紊流邊界層之風洞模擬試驗 3
2-2-1 渦流產生器設計原理 3
2-2-2 粗糙元素設計原理 4
2-3 中性大氣紊流邊界層之風場特性 5
2-4 風洞模擬大氣污染濃度擴散 7
2-4-1 高斯擴散理論 7
2-4-2 煙流擴散尺度 8
2-4-3 結構物對於煙流擴散之影響 9
2-5 相似性法則 9
2-6 濃度因次分析 12
第三章 試驗儀器與量測設計 14
3-1環境風洞介紹 14
3-1-1　中性大氣紊流邊界層之模擬 15
3-1-2　模型配置與設計 15
3-2　試驗流程 15
3-2-1　量測方法與設計 15
3-2-2　濃度場之量測 16
第四章 試驗結果與討論 18
4-1　迫近流場之模擬結果 18
4-2　濃度擴散分佈特性分析與討論 18
4-2-1 試驗濃度擴散分布與探討 18
4-2-2試驗於不同變因下之濃度分析與特性 19
4-2-3各斷面擴散尺度之變化 20
4-2-4各斷面最大濃度值變化 20
4-3探討後排建物表面濃度特性及分析 20
4-3-1後排建築物迎風面濃度分佈 21
4-3-2後排建築物頂部濃度分佈 21
第五章 結論 22
參考文獻 23
附圖 25
謝致 105

hmad, K.,Khare, M.,Chaudhy, K.K., “Wind tunnel simulation studies on dispersion at urban street and intersections-a review”, Journal of Wind Engineering and Industrial Aerodynamics ,Vol. 93,pp. 697-717,2005.
[2] Assimakopoulos, V.D.,ApSimon, H.M.,Moussiopoulos, N., “A numerical study of atmospheric pollutant dispersion in different two-dimensional street canyon configurations”, Atmospheric Environment, Vol. 37, pp. 4037-4049,2003.
[3] Bietry, J., Sacre, C., and Simu, E., “Mean wind profiles and changes of terrain roughness”, Journal of the Structure Division, ASCE, Vol. 104, pp.1585-1593, 1978.
[4] Bing-Chen Wang, Eugene Yee, Fue-Sang Lien, “Numerical study of dispersing pollutant clouds in a built-up environment”, International Journal of Heat and Fluid Flow, Vol. 30, pp. 3-19, 2009.
[5] Businger, J.A., “Aerodynamics of vegetated surface”, Chapter 10, pp.139-165; “Heat and Mass Transfer in the Biosphere”, Vol. 1; “Transfer Processes in the Plant Environment”, Scripton Book Co., Washington D.C., 1974.
[6] Cermak, J.E., “Application of fluid mechanics to wind engineering”, A freeman-scholar lecture, Journal of Fluids Engineering , ASME, Vol. 97, pp. 9-38, 1975.
[7] Cermak, J.E., “Wind tunnel design for physical modeling of atmospheric boundary layer”, Journal of Engineering Mechanics, Vol. 107, pp. 623-642, 1981.
[8] Counihan, J., “Adiabatic atmospheric boundary layer: A review and analysis of data from the period 1880-1972”, Atmospheric Environment, Vol. 9, pp. 871-905, 1975.
[9] Counihan, J., “Simulation of an adiabatic urban boundary layer in a wind tunnel”, Atmospheric Environment, Vol. 7, pp. 673-698, 1973.
[10] Devenport, A.G., “The relationship of wind structure to wind loading”, Proceedings of Symposium on Wind Effects on Building Sand Structure, pp. 53-102,1965.
[11] Gartshore, I.S., and DeCross, K.A., “Roughness element geometry required for wind tunnel simulations of the atmospheric wind”, Transactions of the ASME, Journal of Fluid Engineering, pp. 408-485, 1977.
[12] Irwin, H.P.A.H, “The design of spire foe wind simulation”, Journal of Wind Engineering and Industrial Aerodynamics, Vol. 7, pp. 361-366, 1981.
[13] Jensen, M., “The model law for phenomena in a natural wind”, Ingenioren, Vol. 2, No. 4, 1958.
[14] Kato, M. and Hanafusa, T., “Wind tunnel simulation of atmospheric turbulent flow over a flat terrain”, Atmospheric Environment, Vol. 30, Issue 16, pp. 2853-2858, 1996.
[15] Nakayasa, H. and Nagai, H., “Development of local-scale high-resolution atmospheric dispersion model using large-eddy simulation Part 2:Turbulent flow and plume dispersion around a cubical building”, Journal of Nuclear Science and Technology, Vol. 48, pp. 374-383, 2011.
[16] Salim Mohamed Salim, Riccardo Buccolieri, Andrew Chan, Silvana Di Sabatino, “Numerical simulation of atmospheric pollutant dispersion in an urban street canyon: Comparison between RANS and LES”, Journal of Wind Engineering and Industrial Aerodynamics, Vol. 99, pp. 103-113, 2011.
[17] Seong-Kyu Park, Shin-Do Kim, Heekwan Lee, “Dispersion characteristics of vehicle emission in an urban street canyon”, Science of the Total Environment, Vol. 323, pp. 263-271, 2004.
[18] Sill, B.L., “Turbulent boundary layer profiles over uniform rough surface”, Journal of Wind Engineering and Industrial Aerodynamics, Vol. 31, pp. 147-163, 1988.
[19] Snyder, W.H., “Similarity criteria for the application of fluid models to the study of air pollution meteorology”, Boundary Layer Meteorology, Vol. 3, pp. 113-134, 1972.
[20] Townsend, A.A., “The structure of turbulent shear flow”, Cambridge University Press, pp. 53, 1956.
[21] Vardoulakis, S.,Fisher, B.E.A.,Pericleous, K.,Gonzalez-Flesca, .N., “Modelling air quality in street canyons : a review”, Atmospheric Environment, Vol. 37, pp. 155-182,2003.
[22] Wooding, R.A., Bradley, E.F. and Marshall, J.K., “Drag due to regular arrays of roughness elements of varying geometry”, Boundary-Layer Meteorology, Vol. 5, Num. 3, pp. 285-308, 1973.
[23] 蕭葆羲， “環境風洞基本特性測試及中性大氣紊流邊界層之模擬”，國立臺灣海洋大學河海工程學系環境風洞實驗室技術報告，1998年。