臺灣博碩士論文加值系統

臺北市政府提出城市屋頂綠化設計準則，要求市有新建物屋頂平臺應綠化50%以上面積，以推動建築物綠化與節能、緩解都市熱島效應。然而此一屋頂平臺綠化的規定對於改善週遭微環境甚或減緩熱島效應所能發揮的實際效果為何，尚缺乏精準分析的量化結果可供參考。本研究探討城市綠化設置標準的有效性，探討屋頂綠覆面積對改善微氣候環境與熱島效應效益，藉由計算流體力學(Computational fluid dynamics, CFD)技術進行大尺度模擬，建立選定之城市環境建築群三維立體擬真模型，並整理區域氣象數據以決定模擬分析條件，應用實地量測數據以驗證CFD模擬結果，以評估屋頂綠化對增益都市微環境之效能。研究標地範圍選定為臺北科技大學校區，應用數值模擬軟體建立三維、穩態、不可壓縮氣流與k-ε紊流理論模型，並加入植栽源項設定，以模擬各類型植栽對穿越風之減速和週遭環境冷卻效應，以預測速度與溫度場。本研究模擬比較三種不同情況(無植栽、現況、及臺北科技大學全校園建築物實施50%屋頂綠化)對城市風與熱環境之影響。研究結果顯示植栽形成流阻而降低風場的流動，大型樹種可以有效降低鄰近區域溫度。針對北科大校區周圍環境分析，相較於完全無植栽，現況平均降低1.1℃，最高約可降溫達3.41℃；垂直綠化能有效減緩西曬的影響，而大幅減少北科大校區建築物西側牆面高溫區，整體提升風、熱舒適度。另者，屋頂綠化50%對於1.75m行人高度的風場、溫度場及舒適度影響並不顯著，但仍降低頂樓陽台空間的溫度約0.5~2℃，當擴展屋頂綠化量時亦將擴大植栽降溫影響範圍。風速是影響PET的主要因素，夏季北科大校區行人高度的PET熱感受皆在溫暖(34~38℃)和熱(38~42℃)範圍內。另外，生態水道對周圍1.75m行人高度降低溫度約0.12~1.6℃，於3 m高度影響範圍下，水體垂直方向直接降溫約0.6℃。

The green roof design guides, as proposed by Taipei City Government, request the green coverage ratio of roof platform should be the more than 50% for those newly-built public buildings to promote the energy-conservation of buildings and mitigate the urban island effect of the city. On the other hand, there are no researches conduced to investigate the influences of green roof on the microclimates around building complex. This study aims to conduct computational fluid dynamics (CFD) simulations and measurements for evaluating the microclimate environments around the National Taipei University of Technology (NTUT) campus with a green-roof design in the urban area under a variety of wind conditions. This paper developed the environmental CFD-based analysis procedures to construct a three dimensional (3D) numerical model for replicating the high-density urban building complex. On-site measurements were also conducted to provide the database for code validation. We then applied the verified CFD tool to predict the detailed airflow characteristics of urban environment. Utilizing the NTUT campus as the study site, CFD simulations were conducted to investigate the effects of cooling potential for different greening modifications on urban microclimates by considering the full removal of vegetation in the NTUT campus as Case 1, the existing form of the NTUT campus as Case 2, and realization of 50% green areas on the roofs of all buildings in the NTUT campus as Case 3. The simulated results clearly revealed the functions of vegetation as flow resistance to lower the airflow velocities. Furthermore, large trees can effectively decrease air temperatures in the bordering areas. The predicted temperatures around the NTUT campus were lower than those of Case 2 (with the vegetation completely removed) by 1.1°C on average and up to 3.14°C, respectively. The temperatures near the wall at the west side of building in the NTUT campus were relatively low owing to the shielding by the vertical greening, as compared to the outdoor temperatures of other areas because of the straight exposure to solar radiation and lack of greenery. Besides, the full implementation of 50% green roof measures showed insignificant influences on the wind and thermal comfort at the pedestrian level with a height of 1.75 m. Nevertheless, the air temperatures could generally drop approximately 0.5~2℃ over the balcony space on the top floor. Wind speed is the main factor affecting the index of PET. The thermal sensation at the height of pedestrian level in NTUT campus is “Warm” and “Hot” over summertime. This study identified the amount of greening needed to establish a better urban microclimate environment, suggesting a considerable alleviation of the urban heat island effect with the increased city green space coverage. In addition, the water body can reduce the ambient temperature by 0.12~1.6℃ over the 1.75 m pedestrian height. In the vertical direction of the water body, the average cooling effect is 0.6℃ within a range of 3 m.

摘 要 i
誌 謝 v
目 錄 vi
表目錄 viii
圖目錄 ix
第一章 緒論 1
1.1 研究背景與動機 1
1.2 文獻回顧 2
1.2.1微氣候與植栽 2
1.2.2植栽對周遭環境之影響 2
1.2.3計算流體力學 3
1.2.4舒適度評估指標 3
1.2.5大氣邊界層 5
1.3研究目的 11
第二章 實地量測與實驗方法 13
2.1實驗案例 13
2.2實驗設備 13
2.3實驗方法 18
第三章 理論分析 21
3.1 基本假設與統御方程式 21
3.2 k-ε紊流方程式 22
3.3 植栽源項方程式 22
3.4 水體蒸散方程式 24
3.5 大氣邊界層之風速剖面 24
3.6 PET模型 27
3.7熱輻射模型 28
3.8 數值方法 29
第四章 結果與討論 35
4.1建構模型 35
4.2網格獨立性測試 36
4.3邊界條件 39
4.4實驗量測與CFD模擬驗證 40
4.5 CFD模擬結果及分析 41
4.6校園與周遭環境之風場模擬分析 42
4.7北科大週遭環境之溫度場模擬分析 44
4.7.1屋頂綠化量對城市微氣候之影響 47
4.7.2不同植栽型式之降溫效果 47
4.8北科大週遭環境之濕度場模擬分析 49
4.8 熱舒適度PET評估 50
4.9 水體蒸散效應對城市微氣候之影響 52
第五章 結論 54
參考文獻 56
符號彙編 60

[1]Landsberg, H.E., The Urban Climate. 1981: Elsevier Science.
[2]綠色力量，城市熱島效應研究。
[3] 何育賢，植栽樹型及配置對環境風場之影響，碩士論文，中國文化大學建築及都市計畫研究所，臺北，2009。
[4]A. Dimoudi and M. Nikolopoulou, "Vegetation in the urban environment: microclimatic analysis and benefits," Energy and buildings, 2003. 35(1): p. 69-76.
[5]Shahidan, M.F., et al., "An evaluation of outdoor and building environment cooling achieved through combination modification of trees with ground materials." Building and Environment, 2012. 58: p. 245-257.
[6]Wong, N.H., et al., "Environmental study of the impact of greenery in an institutional campus in the tropics." Building and Environment, 2007. 42(8): p. 2949-2970.
[7]Takakura, T., S. Kitade, and E. Goto, "Cooling effect of greenery cover over a building." Energy and Buildings, 2000. 31(1): p. 1-6.
[8]Srivanit, M. and K. Hokao, "Evaluating the cooling effects of greening for improving the outdoor thermal environment at an institutional campus in the summer." Building and Environment, 2013. 66: p. 158-172.
[9]Niachou, A., et al., "Analysis of the green roof thermal properties and investigation of its energy performance." Energy and buildings, 2001. 33(7): p. 719-729.
[10]Oluwafeyikemi, A. and G. Julie, "Evaluating the Impact of Vertical Greening Systems on Thermal Comfort in Low Income residences in Lagos, Nigeria." Procedia Engineering, 2015. 118: p. 420-433.
[11]Park, M., et al., "Effect of urban vegetation on outdoor thermal environment: Field measurement at a scale model site." Building and Environment, 2012. 56: p. 38-46.
[12]Alexandri, E. and P. Jones, "Temperature decreases in an urban canyon due to green walls and green roofs in diverse climates." Building and Environment, 2008. 43(4): p. 480-493.
[13]Nelson, R.M. and R.H. Pletcher, "An explicit scheme for the calculation of confined turbulent flows with heat transfer." Heat Transfer and Fluid Mechanics Institute, 24 th, Corvallis, Ore, 1974: p. 154-170.
[14]Brohus, H. and P.V. Nielsen, "CFD models of persons evaluated by full-scale wind channel experiments." 1996, Dept. of Building Technology and Structural Engineering.
[15]Ishizu, Y. and K. Kaneki, "Evaluation of ventilation systems through numerical computation and presentation of a new ventilation model." Transactions of SHASE Japan, 1984. 24: p. 47-57.
[16]村上周三, CFD與建築環境設計. 2007: 中國建築工業出版社.
[17]Chen, Q., "Comparison of different models for indoor air flow computations." Numerical Heat Transfer, Part B: Fundamentals, 1995. 28(3): p. 353-369.
[18]Chiang, C.-M., et al., CFD simulation to predict natural ventilation efficiency in a dwelling bedroom with the central horizontal pivot window.
[19]Blocken, B. and J. Carmeliet, "Pedestrian wind environment around buildings: Literature review and practical examples." Journal of Thermal Envelope and Building Science, 2004. 28(2): p. 107-159.
[20]Yang, A.-S., et al., "Estimation of wind power generation in dense urban area." Applied Energy, 2016. 171: p. 213-230.
[21]American Society of Heating, R. and A.C. Engineers, Thermal Environmental Conditions for Human Occupancy: ASHRAE Standard, 2010.
[22]Fanger, P.O., Thermal Comfort: Analysis and Applications in Environmental Engineering. 1982: R.E. Krieger Publishing Company.
[23]Höppe, P., "The physiological equivalent temperature–a universal index for the biometeorological assessment of the thermal environment." International journal of Biometeorology, 1999. 43(2): p. 71-75.
[24]Pickup, J. and R. de Dear. "An outdoor thermal comfort index (OUT_SET*)-part I-the model and its assumptions. in Biometeorology and urban climatology at the turn of the millenium." Selected Papers from the Conference ICB-ICUC. 2000.
[25]Ole Fanger, P. and J. Toftum, "Extension of the PMV model to non-air-conditioned buildings in warm climates." Energy and Buildings, 2002. 34(6): p. 533-536.
[26]Lai, P.-C., et al., "Spatial analytical methods for deriving a historical map of physiological equivalent temperature of Hong Kong." Building and Environment, 2016. 99: p. 22-28.
[27]VDI. Methods for the human biometeorological evaluation of climate and air quality for the urban and regional planning. Part I: Climate. VDI guildline 3787. 1998.
[28]Ketterer, C. and A. Matzarakis, "Mapping the Physiologically Equivalent Temperature in urban areas using artificial neural network." Landscape and Urban Planning, 2016. 150: p. 1-9.
[29]Taleghani, M., et al., "Outdoor thermal comfort within five different urban forms in the Netherlands." Building and Environment, 2015. 83: p. 65-78.
[30]Sanusi, R., et al., "Microclimate benefits that different street tree species provide to sidewalk pedestrians relate to differences in Plant Area Index." Landscape and Urban Planning, 2017. 157: p. 502-511.
[31]Matzarakis, A., F. Rutz, and H. Mayer, "Modelling radiation fluxes in simple and complex environments—application of the RayMan model." International Journal of Biometeorology, 2007. 51(4): p. 323-334.
[32]Matzarakis, A. and H. Mayer, "Another kind of environmental stress: thermal stress. " WHO newsletter, 1996. 18: p. 7-10.
[33]Lin, T.-P. and A. Matzarakis, "Tourism climate and thermal comfort in Sun Moon Lake, Taiwan." International Journal of Biometeorology, 2008. 52(4): p. 281-290.
[34]朱佳仁，環境流體力學，臺北：科技圖書，2003。
[35]Davenport, A.G., "The Relationship of Wind Structure to Wind Loading." 1963: National Physical Laboratory.
[36]內政部營建署編輯委員會，建築物耐震設計規範及解說，營建雜誌社，2005。
[37]Plate, E.J. and H. Kiefer, "Wind loads in urban areas." Journal of Wind Engineering and Industrial Aerodynamics, 2001. 89(14–15): p. 1233-1256.
[38]Wieringa, J., "Updating the Davenport roughness classification." Journal of Wind Engineering and Industrial Aerodynamics, 1992. 41(1): p. 357-368.
[39]Hellmann, G., Ueber die Bewegung der Luft in den untersten Schichten der Atmosphäre. 1914: Kgl. Akademie der Wissenschaften [G.] Reimer.
[40]Simiu, E. and R.H. Scanlan, Wind effects on structures: an introduction to wind engineering. 1986: John Wiley.
[41]台灣綠屋頂暨立體綠化協會, 綠屋頂技術規範.
[42]ANSYS 14.0, (2012). ICEM CFD®, Users manual, ANSYS, Inc.
[43]ANSYS Theory Guide 4.3.3， Realizable k-ε model.
[44]Launder, B.E. and D.B. Spalding, "The numerical computation of turbulent flows." Computer Methods in Applied Mechanics and Engineering, 1974. 3(2): p. 269-289.
[45] B. E. Launder and D. B. Spalding, Lectures in mathematical models of turbulence 1972, London, New York: Academic Press.
[46]Robitu, M., et al., "Modeling the influence of vegetation and water pond on urban microclimate." Solar Energy, 2006. 80(4): p. 435-447.
[47]Bruse, M. and H. Fleer, "Simulating surface–plant–air interactions inside urban environments with a three dimensional numerical model. Environmental Modelling & Software," 1998. 13(3–4): p. 373-384.
[48]Oke, T.R., Boundary layer climates. 2002: Routledge.
[49]Inard, C., D. Groleau, and M. Musy, "Energy balance study of water ponds and its influence on building energy consumption. Building Services Engineering Research and Technology," 2004. 25(3): p. 171-182.
[50]Jang, Y.K. and J.W. Kim, "Total SO2 emission control strategies for the management of air pollution in ulsan industrial complex. Atmospheric Environment ," 1987. 21(3): p. 469-477.
[51]Chen, W.-F. and E. M. Lui, Handbook of structural engineering. 2005: CRC press.
[52]Jang, D., R. Jetli, and S. Acharya, "Comparison of the PISO, SIMPLER, and SIMPLEC algorithms for the treatment of the pressure-velocity coupling in steady flow problems. Numerical Heat Transfer, Part A: Applications," 1986. 10(3): p. 209-228.
[53]Höppe, P. and H. Mayer, "Planungsrelevante Bewertung der thermischen Komponente des Stadtklimas." Landschaft Stadt, 1987. 19: p. 22-29.
[54]Van Doormaal, J. and G. Raithby, "Enhancements of the SIMPLE method for predicting incompressible fluid flows." Numerical heat transfer, 1984. 7(2): p. 147-163.
[55]Isyumov, N. and A. Davenport. "The ground level wind environment in built-up areas. in Proc." 4th Int. Conf. on Wind Effects on Buildings and Structures, Heathrow. 1975.