本研究主要是在使用大渦模擬法去模擬風場中高寬比1:3之方柱所受的風載重，對風載重的模擬結果會做結構反應分析並對照風洞實驗室的實驗結果；探討方向分為三個部份。 
    首先，在第一部份模擬均勻流場中方柱問題主要在確立方柱周圍的網格劃分，我們將方柱放在上游距離入流口8D的位置，並給予Re=1×105的均勻入流；而本文的模擬結果風壓分布對照實驗結果在迎風面結果吻合，但在背風面風壓值偏大，使得拖曳力係數值偏大，雖然如此，由於與前人的模擬結果誤差相近，而史特赫數、擾動昇力係數接近實驗值，因而確立此未來網格劃分。
    第二部份目的則在模擬大氣邊界層風速剖面的風場，因此本研究在入流口給予淡江大學風洞實驗室邊界層，即給予平均風速、紊流能量、紊流消散率，並在地面給予表面剪應力當作在風洞實驗室在地面的粗糙元素，在距離上游入流8D的位置會是後面我們放置建築物的位置，我們希望模擬出來的風場能吻合實驗室的邊界層；模擬結果在風場的1/3高以上在平均風速跟擾動風速可以的到好的剖面，但在下方的擾動風速明顯較小，有明顯的紊流消散在影響這個風場。
    到了第三部份我們要將高寬比1:3之方柱建築物放在距離上游入流8D的大氣邊界層風速剖面的風場裡，所有初始設立的條件都與第二部份相同，即在入流給予平均風速、紊流能量、紊流消散率，並在地面給予表面剪應力；計算結果與實驗數據比較，在拖曳力係數Cd、擾動拖曳力係數Cd’，我們得到的結果都比實驗值大23%，擾動性昇力係數Cl’較為偏大，史特赫數為0.09。

This study is the wind load of the square shaped building with the aspect ratio 1:3 were simulated by large-eddy simulation method. The simulation results of wind load and structural response analysis were compared with those of wind-tunnel test. There are three parts would be study.
        First, it divide grids around the square column mainly. We set the square column at 8D downstream of the inflow boundary, and gives the uniform flow of Re=1×105 in inflow. The results of this study, wind pressure is agree in the windward, but bigger than wind-tunnel test in the leeward. These causes the drag force coefficient to be big. Because the results is closed to the simulation of predecessor. The Strouhal number and lift coefficient close experimentation value. So it confirmed the grids.
         Second, a fully developed boundary layer flow initially generated in the wind tunnel was selected as the target flow field. Additional a fully developed boundary layer flow of the wind tunnel test, i.e., mean wind speed, kinetic energy and dissipation rate. And additional the surface shear was set on the ground to represent the effects of wind tunnel surface roughness elements. The upper twe-third of the profile is also agreed well with target flow. The flow in the lower one-third of the calculation domain has excessive energy dissipation, with RMS wind speed lower then the target flow field.
         In the third stage of this project, the 1:1:3 square shaped building model was installed at 8D downstream of the inflow boundary. All the initial conditions are set up with the second part of the same, i.e., add mean wind speed, kinetic energy and dissipation rate at the inflow boundary, and shear stress on the ground. The result compare with wind tunnel test,the mean drag force coefficient and RMS drag force coefficient value are found 23% larder than wind tunnel measurement, and lift coefficient is too large. The Strouhal number is 0.09.

目錄	I
表目錄	III
圖目錄	IV
第1章 緒論	1
1-1 前言	1
1-2 研究動機	1
1-3 研究方法	2
1-4 研究結果	3
第2章 文獻回顧	4
2-1 背景說明	4
2-2 相關研究	4
第3章 結構風工程之基礎理論	7
3-1 大氣邊界層流場特性概述	7
3-1-1 平均風速剖面	7
3-1-2 紊流強度	9
3-1-3 紊流長度尺度	10
3-1-5 擾動風速頻譜	12
3-2 鈍體氣動力現象	13
3-3 結構物之風載重	15
3-3-1 順風向風力作用	16
3-3-2 橫風向風力作用	17
3-3-3 扭轉向風力作用	18
第4章 計算流體力學軟體介紹與方法	19
4-1 計算流體力學	19
4-1-1 計算流體力學的工作步驟	19
4-1-2 計算流體力學的應用領域	21
4-2 FLUENT使用介紹	21
4-2-1 網格	22
4-2-1 數值方法	24
4-2-2 紊流模式	28
4-2-3 邊界條件	37
第5章 問題描述及計算過程	39
5-1數值模擬步驟說明	39
5-2兩端板間矩柱分析	40
5-2-1 兩端版間方柱分析之條件設定	40
5-3 數值模擬大氣邊界層分析	45
5-3-1 模擬大氣邊界層之條件設定	45
5-4 高層建築表面風壓特性分析	49
5-4-1 高層建築表面風壓特性之條件設定	49
第6章 分析結果與討論	55
6-1兩端板間矩柱結果分析	55
6-1-1 結果分析	55
6-1-2 小結	61
6-2 數值模擬大氣邊界層結果分析	61
6-2-1 結果分析	61
6-2-2 小結	66
6-3高層建築表面風壓特性結果分析	66
6-3-1 結果分析	66
6-3-2 小結	75
第7章 設計風載重分析	76
7-1 模擬相關數據之結構特性	76
7-2 數值模擬資料之歷時分析	76
7-3 風載重設計結構分析	77
7-3-1 結構反應	78
第8章 結論與建議	82
8-1 結論	82
8-2 建議	84
參考文獻	85


表目錄
表3-1 指數律參數建議值	8
表3-2 對數律參數建議值	9
表3-3 常用Β值與Z0的關係	10

表6-1 本研究與實驗結果、其他計算值比較	60
表6-2 風力係數結果與實驗比較	70

表7-1 MIDAS分析實場建築物幾何尺寸及結構特性相關參數	78
表7-2 建築物受風力的平均基底剪力	79
表7-3 建築物受風力歷時的結構分析的最大及最小基底剪力	79
表7-4 建築物受風力歷時頂樓位移	81

 
圖目錄

圖3-1 M隨ZO遞增之關係圖[17]	11
圖3-2 鈍體分離流及渦漩示意圖	15

圖 4-2 文獻[31]，數值模擬步驟	20
圖 4- 3 FLUENT[30]提供各種網格元素	23
圖 4- 4 FLUENT在速度及壓力求解疊代方法的選用視窗	24
圖 4-5 在FLUENT對接近壁面的處理[30]	33

圖5-1 本研究模擬過程	39
圖5-2 SONG, C.-S. AND PARK, S.-O.計算域	40
圖5-3 兩端版間矩柱分析之計算域大小	41
圖5-4 兩端版間矩柱分析之網格繪製細節（XY向）；	42
圖5-5 兩端版間矩柱分析之網格繪製細節（Z向）；	42
圖5-6 兩端版間矩柱分析之網格；	43
圖5- 7 兩端版間矩柱分析之邊界條件設定圖示	44
圖5-8 數值模擬大氣邊界層分析之計算域大小	45
圖5-9 模擬大氣邊界層之網格繪製細節（XY向）；	46
圖5-10 模擬大氣邊界層之網格繪製細節（Z向）；	46
圖5-11模擬大氣邊界層之網格圖示(XZ向)；	47
圖5-12模擬大氣邊界層之網格圖示(YZ方向)	47
圖5-13 模擬大氣邊界層之邊界條件設定圖示	48
圖5-14 高層建築表面風壓特性分析之計算域大小	50
圖5-15高層建築表面風壓特性之網格繪製細節（XY向）；	51
圖5-16高層建築表面風壓特性之網格繪製細節（XZ向）	51
圖5-17高層建築表面風壓特性之網格圖示(XY向)；	52
圖5-18高層建築表面風壓特性之網格圖示(XZ向)	52
圖5-19 高層建築表面風壓特性之邊界條件設定圖示	53

圖6-1 尾流區中心線之平均順風向速度分布CFD與實驗比較圖	56
圖6-2 方柱表面平均風壓分布之CFD與實驗值比較圖	57
圖6-3 風力係數歷時圖；（A）CASE A1，（B）CASE B，（C）CASE A2	58
圖6-4 昇力係數頻譜圖；（A）CASE A1，（B）CASE B，（C）CASE A2	59
圖6-5取值位置（圖6-8~圖6-19）示意圖	63
圖6-6 平均風速剖面	63
圖6-7 紊流強度	63
圖6-8 X/D=8，H/D=3的風速頻譜與實驗比較	64
圖6-9 X/D=8，H/D=2的風速頻譜與實驗比較	64
圖6-10 入流斷面(X/D=0，H/D=3)	64
圖6-11 風速頻譜(X/D=1，H/D=3)	64
圖6-12 風速頻譜(X/D=2，H/D=3)	64
圖6-13 風速頻譜(X/D=3，H/D=3)	64
圖6-14 風速頻譜(X/D=4，H/D=3)	65
圖6-15 風速頻譜(X/D=5，H/D=3)	65
圖6-16 風速頻譜(X/D=6，H/D=3)	65
圖6-17 風速頻譜(X/D=7，H/D=3)	65
圖6-18 風速頻譜(X/D=6，H/D=3)	65
圖6-19 風速頻譜(X/D=6，H/D=3)	65
圖6-20 高寬比3平均表面風壓係數；	68
圖6-21 高寬比3擾動表面風壓係數；	69
圖6-22 CFD建築物風力係數歷時	70
圖6-23 建築物2/3高度各點風壓位置（圖6-24~圖6-27）示意圖	71
圖6-24 建築物2/3高度迎風面風壓頻譜	72
圖6-25 建築物2/3高度右側風面風壓頻譜	72
圖6-26 建築物2/3高度背風面風壓頻譜	73
圖6-27 建築物2/3高度左側風面風壓頻譜	73
圖6-28 建築物風力係數頻譜；（A）順風向，（B）橫風向	74
圖6-29 建築物高度逼近流的風速頻僕	74

圖7-2 本研究深寬比1、高寬比3之MIDAS結構模型	77
圖7-3 建築物受力各樓層位移之最大反應	80
圖7-4 建築物受力之各樓層剪力	80
圖7-5 建築物受力之反應頻譜	81

[1].	Bosch, G., Rodi,W., 1998. Simulation of vortex shedding past a square cylinder with different turbulence models. International Journal for Numerical Methods in Fluids 28, 601–616.
[2].	Lee, S.S., 1997. Unsteady aerodynamics force prediction on a square cylinder using k–ε turbulence model .Journal of Wind Engineering and Industrial Aero - dynamics 67–68,79–90.
[3].	Lyn, D.A., Einav, S., Rodi, W., Park, J.H., 1995. A laser-Doppler velocimetry study of ensemble-averaged characteristics of the turbulent near wake of a square cylinder. Journal of Fluid Mechanics 304, 285–319
[4].	Okajima, A. (1990) “Numerical Simulation of Laminar and Turbulent Flow Around Rectangular Cylinders” International Journal for Numerical Methods in Fluids, Vol33, pp.171-180
[5].	Tamura, T. and Kuwahara, K. (1990), " Numerical Study of Aerodynamic Behavior of a Square Cylinder ," J. Wind Engg. and Ind. Aerod. ,V.33 ,pp. 161-170.
[6].	Murakami, S.,Mochida, A. (1988), "3-D Numerical Simulation of Airflow around a Cubic Model by Means of the K- Model ," J. Wind Engg. and Ind. Aerod., Vol.31, pp.283-303
[7].	Murakami, S.,Mochida, A. and Hayashi, Y. (1990), "Examining the K-Model by Means of A Wind Tunnel Test and Large-Eddy Simulation of the Turbulence Structure Around A Cube ," J. Wind Engg. and Ind. Aerod., Vol.35, pp.87-100
[8].	Murakami, S.,Mochida, A. (1995), "On Turbulent Vortex Shedding Flow Past 2D Square Cylinder Predicted by CFD," J. Wind Engg. and Ind. Aerod., Vol.54/55, pp.191-211
[9].	K. Nozawa, T. Tamura, Large eddy simulation of the flow around a low-rise building immersed in a rough-wall turbulent boundary layer J. Wind Eng. Ind. Aerodyn. 90 (2002) 1151–1162.
[10].	Tetsuro Tamura , Kojiro Nozawa, Koji Kondo, AIJ guide for numerical prediction of wind loads on buildings. J. Wind Eng. Ind. Aerodyn. 96 (2008) 1974–1984.
[11].	Ohtake, K., 2002. Takenaka time-sequential database for wind loading on buildings (Private Communication).
[12].	Kawai, H., 1982. Pressure on three dimensional prisms in a turbulent boundary layer. in: Proceeding of the Seventh National Symposium on Wind Engineering, pp. 67–74.
[13].	Girimaji, S., Sreenivasan, R., Jeong, E., 2003. PANS turbulence model for seamless transition between RANS, LES: fixed-point analysis and preliminary results, In: Proceedings of ASME FEDSM’03 2003 fourth ASME-JSME Joint Fluids Engineering Conferences, Honolulu, Hawai.
[14].	Lakshmipathy,S.,Girimaji,S.S.,2006.Partially-averagedNavier–Stokesmethod for turbulent flow: k–o model implementation. AIAA paper 2006 - 119.
[15].	Frohlich, J. ,Terzi, D.V., 2008. Hybrid LES/RANS methods for the simulations of turbulent flows. Progressin Aerospace Science 43, 349 – 377.
[16].	Song, C.-S., Park, S.-O., Numerical simulation of flow past a square cylinder using Partially-Averaged Navier–Stokes model. J. Wind Eng. Ind. Aerodyn. (2009)
[17].	Davenport, A.G., 1956, “The Relationship of Wind Structure to Wind Loading”, Proc, Symp. on Wind Effects on Buildings and Structures, Vol. 1, National Physical Laboratory, Teddington, U.K. Her Majesty’s Stationary Office, London, p.53-102
[18].	American National Standard A58.1-1982 Minimun American National Standard Institute, Inc., New York.
[19].	營建雜誌社, 2006, “建築物耐風設計規範及解說”.
[20].	Emil Simiu, Rebort H. Scanlan, 1986, “Wind Effects on Structures” 2nd edit., John Wiley & Sons.
[21].	Davenport, A.G., 1961, “The Spectrum of Horizontal Gustiness Near the Ground in High Winds”, J. Royal Meteorol. Soc., 87, p194-211
[22].	Kawai, H., 1998, “Effect of corner modifications on aeroelastic instabilities of tall buildings”, J. of Wind Eng. & Ind. Aero., Vol. 74-76, p.719-729.
[23].	Huang P., 2001, “Wind-induced interference effects on tall buildings”, Ph.D. Thesis. Tongji University, China
[24].	Patankar, S. V. “Numerical Heat Transfer and Fiuid Flow”, Hemisphere Publish Co. (1980)
[25].	Chu, C.R. and Soong, C. K “Numerical Simulation of wind-induced entrainment in a stably stratified water basin”, J. of Hydraulic Research, Vol.35 No.1 (1997)
[26].	R.I. Issa , Solution of the implicitly discretised fluid flow equations by operator-splitting incompressible fluid flows. Numerical Heat Transfer, 7:147-163, 1984.
[27].	D.M. Hargreaves, N.G. Wright, On the use of the k–ε model in commercial CFD software to model the neutral atmospheric boundary layer. Building and Environment 44 (2009) 621–632
[28].	Smagorinsky, J. (1963), General Circulation Experiments with the Primitive Equations , Month Weather Review , Vol.93, No.99, pp.99-164.
[29].	Gambit 2.16 User Guide, http://www.fluent.com (2004)
[30].	Fluent 6.1 User Guide, http://www.fluent.com (2004)
[31].	B. E. Launder and D. B. Spalding. Lectures in Mathematical Models of Turbulence. Academic Press, London, England, 1972.
[32].	王福軍, 計算流體動力學分析, 北京, 清華大學出版社.