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    Please use this identifier to cite or link to this item: http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/44637

    Title: 紊流對二維矩柱分離剪力層發展之影響
    Other Titles: The development of separation shear layer of rectangular cylinder in 2-D turbulent flows
    Authors: 盧博堅;鄭啟明;楊威
    Contributors: 淡江大學水資源及環境工程學系;淡江大學土木工程學系
    Keywords: 紊流強度;紊流長度尺度;分離剪力層;Turbulence intensity;Turbulence length scale;Separated shear layer
    Date: 1995-06
    Issue Date: 2013-03-12 11:26:12 (UTC+8)
    Publisher: 新竹市:中華民國力學學會
    Abstract: 本文藉著風洞實驗來探討均勻紊流場流經二維矩形斷面柱體後之分離剪力層發展情形。實驗之控制參數為:一、逼進流場紊流強度;二、紊流長度尺度;三、模型側風面高度與迎風面寬度之比值。實驗以裂膜探針對模型之分離剪力層進行速度量測,同時以壓力計由模型側面之壓力孔來量測風壓。以求得之速度剖面和壓力場之分佈,來說明前述控制參數對分離剪力層的影響。研究結果顯示矩形模型之分離剪力層隨紊流強度增加而變厚,如有再接觸現象的發生,則會縮短分離氣泡的長度,亦即紊流強度會增加剪力層之曲率。另外結果也顯示,模型側面壓力場之分佈,再接觸前受逼進流場所影響,再接觸後則受下游渦旋區所主控。模型平均壓力和擾動壓力皆隨高寬比之增加而減少。至於紊流長度所造成之影響則並不明顯。An experimental investigation was carried out to study the characteristics of the separated shear layer of rectangular cylinders in two dimensional homogeneous turbulent flows. The data were collected due to the variations of (1) turbulence intensity (2) turbulence length scale (3) depth-to-height ratio. Simultaneously measurements of the surface pressure on the lateral side and the shear layer velocity were performed using pressure taps and split-hot-film respectively. The results were utilized to characterize the effects of the above variations on the development of the separated shear layer. The result shows that turbulence intensity increases the thickness of the separated shear layer and decreases the length of separation bubble when reattachment occurs. In other words turbulence intensity will increase the curvature of the shear layer. The pressure distribution on the lateral side before reattachment zone is influenced by the approach flow. However, after the reattachment zone the mean pressure coefficient and rms pressure coefficient decrease.
    Relation: 力學:中國力學學會期刊=The Chinese Journal of Mechanics 11(2),頁117-123
    Appears in Collections:[Graduate Institute & Department of Civil Engineering] Journal Article
    [Graduate Institute & Department of Water Resources and Environmental Engineering] Journal Article

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