本研究係利用大氣環境風洞，搭配適當之渦流產生器與粗糙元素，模擬都市地形之中性大氣邊界層，進行模擬連續溢漏重質氣體在不同斜坡角度梯型地形與街道之擴散特性。重質氣體溢漏源，位於梯型地形模型表面正中央，二維梯型地形模型上風坡與下風坡之斜坡角度為15°與30°，街道建築高度分別為地形模型高度之1.5倍與2倍，梯型地形與街道建築之間距為地形模型高度之1倍與3倍。
由實驗結果得到以下結論：
(1) 迫近流場模擬結果顯示，帄均風速、紊流強度等皆與Counihan之建議值符合。
(2) 梯型地形斜坡角度由15°增加為30°時，下風坡面產生回流渦旋，使溢漏重質氣體濃度累積，造成氣團抬升現象。
(3) 梯型地形後方街道建築高度增加，將使重質氣體累積且抬升情形更加明顯。
(4) 梯形地形與其後方街道建築距離越近，將使重質氣體往側向擴散現象越顯著。
(5) 當梯型地形與街道建築間距變小時，街道建築之迎風向表面濃度將增加。又當街道建築高度增加時，會使街道建築之迎風向表面濃度累積位置上升。

In the present study, wind tunnel experiments were conducted to investigate the dispersion characteristics of continuous spill of heavy gas from trapezoidal terrain with different slope angles which interacting with building.
In the experiments, the spill source located at the surface center of the trapezoidal terrain. The trapezoidal terrain with equal upwind and downwind slope which were 15°and 30°. Building heights in the street were1.5 times and 2 times of the terrain model height. The distance between the trapezoidal terrain model and building behind the street was one time and three times of terrain model height. Effects of the terrain slope angles, building heights, and distance between the terrain model and building on the heavy gas dispersion, such as concentration distribution, dispersion parameters were investigated.

目次
摘要 I
ABSTRACT II
目次 III
圖目次 VII
符號說明 XI
第一章 導論 1
1.1 前言 1
1.2 研究動機與目的 1
1.3 文獻回顧 1
1.4 研究方法與內容 3
第二章 風洞模擬之擴散理論 5
2-1 中性大氣紊流邊界層 5
2-2 中性大氣紊流邊界層風場特性 5
2-2.1 中性大氣邊界層厚度 5
2-2.2 平均風速剖面 6
2-2.3 紊流強度 7
2-2.4 紊流積分尺度 8
2-2.5 紊流能譜 9
2-3 大氣紊流邊界層之風洞模擬 9
2-3.1 風洞模擬之相似性法則 10
2-3.2 渦流產生器設計原理 12
2-3.3 粗糙元素設計原理 12
2-4 重質氣體因次分析探討 13
第三章 實驗配置與設計 15
3-1 實驗流程 15
3-2 實驗儀器 15
3-2.1 大氣環境風洞 15
3-2.2 風場量測系統 16
3-2.3 濃度量測與分析系統 17
3-3 實驗設計 18
3-3.1 實驗設計條件 18
3-3.2 實驗模型設計 19
3-3.3 迫近流場模擬設計與量測 20
3-3.4 環境風場量測 20
3-3.5 溢漏源設計 21
3-3.6 濃度場量測 21
3-3.7 濃度場採樣點設計 21
第四章 實驗結果與分析 23
4-1 迫近流場模擬結果 23
4-1.1 平均風速剖面 23
4-1.2 紊流強度剖面 24
4-1.3 紊流頻譜 24
4-2 擴散尺度分析 25
4-3 重質氣體擴散特性 26
4-3.1 濃度場分佈特性分析 26
4-3.2 地形斜坡θ=15°及地形與建物間距W為1H各街道高度濃度擴散 特性 26
4-3.3 地形斜坡θ=30°及地形與建物間距W為1H各街道高度濃度擴散 特性 27
4-3.4 地形斜坡θ=15°及地形與建物間距W為3H各街道高度濃度擴散 特性 27
4-3.5 地形斜坡θ=30°及地形與建物間距W為3H各街道高度濃度擴散 特性 28
4-3.6 地形斜坡對濃度擴散特性效應 28
4-3.7 斜坡地形與建物距離對濃度擴散特性效應 29
4-4 建物表面濃度擴散特性 29
4-4.1 地形斜坡角度θ=15°與地形斜坡θ=30°之表面濃度擴散特性比較 30
4-4.2 斜坡地形與建物距離改變時之表面濃度擴散特性比較 30
4-5 排放源下風處各斷面最大濃度變化 30
4-6 排放源下風處各斷面地表高度(Z=0)濃度變化 31
第五章 結論 33
參考文獻 35
附圖 37

1. Britter, R. E., “Atmospheric Dispersion of Dense Gases”, Ann. Rev. Fluid Mech.. Vol. 21, pp. 317-44 (1989).
2. Castro,Ian. P., “Removal of Slightly Heavy Gases from a Valley by Crosswinds”, Journal of Hazardous Materials, Vol. 34, pp. 271-293 (1993).
3. Cermak, J.E., “Wind tunnel design for physical modeling of atmospheric boundary layer”, Journal of Engineering Mechanics, ASCE, Vol. 107, pp. 623-642, (1981).
4. Counihan, J., “Adiabatic Atmospheric Boundary Layers: A Review and Analysis of the Data from the Period 1880-1972”, Atmospheric Environment, Vol. 9, pp. 871-905 (1975).
5. Donat, J. and Schatzmann, M., “Wind Tunnel Experiments of Single-Phase Heavy Gas Jets Released Under Various Angles into Turbulent Cross Flows”, Journal of Wind Engineering and Industrial Aerodynamics, Vol. 83, pp. 361-370 (1999).
6. Irwin, H. P. A. H., “The Design of Spires for Wind Simulation”, Journal of Wind Engineering and Industrial Aerodynamic, Vol. 7, pp. 361-366 (1981).
7. Lateb, M., Masson, C., Stathopoulos, T. and Bedard, C., “Numerical simulation of pollutant dispersion around a building complex” Building and Environment., Vol. 45, pp. 1788-1798, (2010).
8. Lateb, M., Masson, C., Stathopoulos, T. and Bedard, C., “Effect of stack height and exhaust velocity on pollutant dispersion in the wake of a building” Atmospheric Environment., Vol. 45, pp. 5150-5163, (2011).
9. Mavroidis, I., Griffiths, R. F. and Hall, D. J., “Field and wind tunnel investigation of plume dispersion around single surface obstacles” Atmospheric Environment., Vol. 37, pp. 2903-2918, (2003).
10. Meroney, R. N., “Perspectives on Air Pollution Aerodynamics”, Wind Engineering into the 21th Century, Larsen, Larose &; Livesey(eds), pp. 79-90 (1999).
11. Meroney, R. N.., “Wind-Tunnel Experiments on Dense Gas Dispersion”, Journal of Hazardous Materials, Vol.6 ,pp.85-106 (1982).
12. Ramsay, S. R., “Dense Gas Dispersion in Complex Setting: Part 1-The Effect of Obstacles”, Wind Climate in Cities, pp. 575-605 (1995).
13. Ramsay, S. R., “Dense Gas Dispersion in Complex Setting: Part 2-The Effect of Topography”, Wind Climate in Cities, pp. 607-629 (1995).
14. Schatzmann, M., Snyder, W. H., Lawson, R. E., “Experiments with Heavy Gas Jets in Laminar and Turbulent Cross Flows”, Atmospheric Environment, Vol. 27A, pp. 1105-1116 (1993).
15. Schatzmann, M., “Accidental Release of Heavy Gases in Urban Areas”, Wind Climate in Cities, pp. 555-574 (1995).
16. Townsend, A. A., “The Structure of Turbulent Shear Flow”, Cambridge University Press, pp. 53 (1956).
17. 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」，國立台灣海洋大學河海工程學系環境風洞實驗室技術報告，NTOU-EWTL-1998-01 (1998)。
18. 吳孟訓，「環境風洞模擬重質氣體之擴散特性」，國立台灣海洋大學河海工程學系碩士論文(2000)。
19. 胡瑞顯，「重質氣體經不同斜坡角度地形之擴散特性風洞實驗」，國立台灣海洋大學河海工程學系碩士論文(2011)。
20. 王詩銘，「風洞試驗研究點源排放在不同排列之相同雙棟建築物之擴散特性」，國立台灣海洋大學河海工程學系碩士論文(2012)。