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    Title: 各種地況之大氣邊界層特性研究
    Other Titles: Characteristics of atmospheric boundary layers developed over various terrains
    Authors: 黃國峰;Huang, Kuo-Feng
    Contributors: 淡江大學土木工程學系碩士班
    鄭啟明;Cheng, Chii-ming
    Keywords: 風洞實驗;大氣邊界層;標準地況;複雜地形;wind tunnel;Atmospheric boundary layer;standard terrain;complex terrain
    Date: 2014
    Issue Date: 2015-05-04 09:56:37 (UTC+8)
    Abstract: 隨著科技的發展、醫學的進步,人口有逐漸成長的現象,但需要在有限的土地上求生活空間,所以建築物有向上發展的趨勢,加上政府近年來推動都市更新的計畫,都市中存在著越來越多的高層建築。高層建築除了受到地震力的影響,對風力的敏感程度也會增加,因此耐風設計對結構物的反應是高層建築設計裡重要的一環。在風工程研究中,無論是風洞實驗、數值模擬,最主要的目的都是在實場上的耐風設計及風環境評估,例如相鄰建築物間風力的相互作用,與建築物周遭環境的行人風場,皆與生活品質與居住安全有著密不可分的關係,而台灣地區颱風所造成之財物損失,位居台灣所有天然災害的第一位,解決的方法唯有對風場行為有完整的了解,才能以工程的手段來降低風災對工程設施的破壞,進而提高人類居住環境的品質。因此,風工程儼然成為一門重要的課題。但實場量測儀器昂貴,所量測數據非常有限,因此可以利用風洞實驗所做出來的結果去補足在實場中無法量測到的資料數據,做為設計及評估上的參考。本研究以風洞模擬實驗為主分作兩個部分,一為符合標準地況自然風場之風洞模擬,在實場量測中我們不易得知大氣邊界層真實的紊流特性,透過風洞實驗的結果,我們能更了解該地況的邊界層特性。但如果要進行一個真實地況的大氣邊界層模擬,在製作地況縮尺模型上需要耗費大量的人力、物力。本研究希望能將真實地物,以一簡單的方法、公式模擬成均勻方塊的粗
    糙元素,代替原實場地形來進行風洞實驗,以節省許多的經費與時間,此為
    符合標準地況自然風場之風洞模擬。二為複雜地形自然風場之風洞模擬,由於台灣地窄人稠,各地形皆相鄰,許多建物皆建築在山坡、山腳上,大氣邊界層特性實為複雜,亦與各國不同,本研究最終以台灣北部淡水北投一帶大屯山系山腳一處俗稱小坪頂的山區平地,為綜合型的複雜地形場址,加上前述的符合標準地況自然風場之風洞模擬,以進行了解台灣本地的大氣邊界層特性,進而建立出適合台灣本地的耐風設計規範及風洞實驗技術。
    The simulation of turbulence boundary layers in this study can be divided into two parts. The first part is simulation of flow field developed over terrains that compliance with the definitions of the terrain categories in the building wind code. Since current field measurements can only provide reliable mean wind speed profile. Properly simulated turbulence boundary layer is the best and only viable means to acquire turbulence features of the atmospheric boundary layers. Besides simulating flow fields via scaled terrain models, the thesis further studied the procedure to develop equivalent floor roughness elements to generate turbulent boundary layers over urban, suburban and open terrains. The second part of this thesis is the wind tunnel simulation of wind field over complex terrain. A 1/5000 mountainous terrain model centered at Xiaopingding, tamsui in the northeastern corner of Taiwan was built. Wind tunnel measurements were then compared with field measurement of Lidar and numerical simulation by LES. The initial result indicates that wind tunnel simulation of rugged terrain has its limitations. In real life, hills and mountains are not homogenous terrains. The shape and geographic lay out of high mountains would significantly distort the approaching flow. This geographic effect can be extremely difficult properly simulated in a fixed sized wind tunnel test section. More works need to be done in this subject.
    Appears in Collections:[土木工程學系暨研究所] 學位論文

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