Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/13657
標題: 應用PIV於低雷諾數下矩形柱體來流端穩態馬蹄型渦流三維特性之探討
Study on the Characteristics of Steady Horseshoe Vortex near the Juncture of a Rectangular Pillar and a Flat Plate at low Reynolds number
作者: 翁健銘
Weng, Ching Ming
關鍵字: Horseshoe vortex;馬蹄渦
出版社: 土木工程學系
摘要: 
本研究利用質點影像測速儀(PIV)與雷射光纖度普勒(FLDV),以邊界層流為來流條件,將矩形柱體之來流端穩態馬蹄型渦流結構作一細部分類,並對於不同渦流結構之流場以拓樸學理論進行渦流分析與水平速度剖面之探討。在不同渦流結構定量研究方面,發現不論主渦渦心位置、停滯點高度、模型前端下降流與主渦環流量強度皆可在適當的參數無因次後,與H /δ呈現線性變化的關係。
在不同x-y剖面探討下,發現馬蹄型渦流由中心軸向矩形柱體兩旁運動時,其主渦渦心有向矩形柱體移動之趨勢,且高度幾乎不變;而不同x-y剖面之矩形柱體前端下降流與環流量之定量分析中,得知下降流與環流量是隨著馬蹄型渦流由中心軸往兩旁移動時,有著逐漸遞減之趨勢。在矩形柱體前端x-z剖面之流場特性中,在最接近壓克力底板之剖面可明顯看出流場中有一如馬蹄型之流場,且在矩形柱體前端有著強烈的逆流及側向流;而遠離壓克力底板後其流場即無明顯之逆流及側向流。

The characteristics of steady horseshoe vortex system near the juncture of a square pillar and a horizontal plate were studied experimentally, using particle image velocimetry (PIV), fiber laser Doppler velocimetry (FLDV). The structure of horseshoe vortex was observed at low Reynolds number when flow parameters changed. Detail characteristics of the steady horseshoe vortex behavior, including the position of primary vortex core, the position of stagnation point on the model, down-flow velocity profile, and the circulation of primary vortex are guantified and discussed in detail in the present study.
The research in different x-y sections shows that the vortex core moves to the square pillar when the horseshoe vortex moves from the center to the side. The analysis in different x-y sections reveals that down-flow velocity profile and the circulation reduce when the horseshoe vortex move from the center to the side. The quality in different x-z sections exhibits that strange reflux and side flow are in front of the square pillar when a horseshoe vortex field near the bottom board and no distinct reflux or side flow exit far away the bottom plate.
URI: http://hdl.handle.net/11455/13657
Appears in Collections:土木工程學系所

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