臺灣博碩士論文加值系統

本試驗內容為探討平行風向街谷地形對氣旋性汙染物排放的影響，分析平行風向街谷地形之地表面風速、建物上方風場及氣懸性汙染物擴散情形。
(一) 利用臺灣海洋大學環境風洞實驗室配合渦流產生器與粗糙元素模擬出符合Counihan(1975)實場調查結果建議值之都市地形中性大氣紊流邊界層。
(二) 當街谷間距寬度(S)與建物高度(H)之比值(S/H)，增加(從0.5增至1.5)。街谷內部風速變化引發之迴流越不明顯，導致汙染物於街谷內之擴散作用變得相對地顯著。
(三) 當街谷左棟與右棟建物高度差之比值(L/H)於為0.5時，街谷內之污染物擴散較(L/H)為1時顯著。相對高度越大越利於污染物擴散。

This study employed the wind tunnel to investigate the flow and dispersion characteristics of elevated point source discharging into street canyon. Spire arrays and roughness elements were deployed to generate a thick turbulent boundary layer in the wind tunnel. The neutral atmospheric turbulent boundary layer flow was simulated as the approaching flow which had the power-law mean velocity profile with exponent n=0.27. The simulated turbulent boundary layer with turbulence intensity close to the ground is about 0.2~0.24. The simulation of approaching flow is found in agreement with the results proposed by Counihan(1975).
The effect of width of street canyon and building height difference of two sides in canyon on the pollution dispersion were explored.
Results show that the wind flow smoothly and it is favorable to pollution dispersion when the width of street canyon becomes wider. The in crease of building height difference results in the better dispersion of pollution in the street canyon.

摘要 I
ABSTRACT II
目次 III
表目次 V
圖目次 VI
第一章　導論 1
1-1　前言 1
1-2　文獻回顧 1
1-3　研究方法 1
第二章　風洞模擬試驗之基本理論 3
2-1　中性大氣紊流邊界層風速剖面之特性 3
2-1-1　平均風速剖面 3
2-2　中性大氣紊流邊界層之風場性質 4
2-2-1　相似性法則 4
2-2-2　渦流產生器(spire)之設計原理 6
2-2-3　粗糙元素(roughness elements)之設計原理 7
2-3 風速與濃度因次分析 7
2-4　高斯擴散理論 10
第三章　試驗儀器與試驗設計 12
3-1　試驗儀器 12
3-1-1　大氣環境風洞 12
3-1-2　風場量測儀器 13
3-1-3　地表面風速計 13
3-1-4　濃度場量測之儀器 13
3-2　試驗設計 14
3-2-1　模型設計 14
3-2-2　追蹤氣懸性氣體設計 14
第四章　試驗結果與討論 16
4-1　迫近流場之模擬結果 16
4-2 風速分佈特性分析 16
4-2-1　地表面風速 16
4-2-2　建物上方垂直剖面風速分佈 16
4-2-3　建物上方平面風速分佈 17
4-3　水平濃度擴散分佈特性分析 17
4-3-1　建物高度對水平濃度擴散特性之影響 18
4-3-2　街谷間距對水平濃度擴散特性之影響 18
4-4　垂直剖面濃度擴散特性分析 19
4-4-1　建物高度對垂直剖面濃度擴散特性之影響 19
4-4-2　街谷間距對垂直剖面濃度擴散特性之影響 19
4-5　垂直剖面濃度之對比分析 20
4-6　水平擴散尺度分析 20
4-6-1　建物高度對水平擴散尺度之影響 20
4-6-2　街谷間距對水平擴散尺度之影響 20
4-7　垂直剖面擴散尺度分析 21
4-7-1　建物高度對垂直剖面擴散尺度之影響 21
4-7-2　街谷間距對垂直剖面擴散尺度之影響 21
4-8　垂直剖面濃度最大值 21
第五章　結論 22
參考文獻 23
附表 25
附圖 26
謝誌 112

[1] 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.
[2] 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.
[3] 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.
[4] 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.
[5] Cermak, J.E., “Wind tunnel design for physical modeling of atmospheric boundary layer”, Journal of Engineering Mechanics, Vol. 107, pp. 623-642, 1981.
[6] 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.
[7] Counihan, J., “Simulation of an adiabatic urban boundary layer in a wind tunnel”, Atmospheric Environment, Vol. 7, pp. 673-698, 1973.
[8] 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.
[9] Eurocode 1, “Basis of Design and Actions on Structures—Part 2-4: Actions on Structures –Wind Actions”, European Prestandard ENV 1991-1-2-4.
[10] 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.
[11] 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.
[12] Jensen, M., “The model law for phenomena in a natural wind”, Ingenioren, Vol. 2, No. 4, 1958.
[13] 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.
[14] L. Soulhac, P. Salizzoni, “Dispersion in a street canyon for a wind direction parallel to the street axis”, J. Wind Eng. Ind. Aerodyn, Vol. 98, pp. 903-910, 2010.
[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] Von Karman, T., “Progress in the Statistical Theory of Turbulence”, Proceedings of National Academy of Science, Vol.34, pp.530-539, 1948.
[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。