臺灣博碩士論文加值系統

本研究探討並列之二維柱體並列時，因前後相對位置不同，所造成對其下游流場之渦流溢放特性以及縫隙流之流場不穩定特性之影響。本研究所探討之二維柱體的截面形狀包括圓柱、方柱及平板三種，探討平板分別與圓柱或方柱並列時，其下游尾流與縫隙流的流場特性。主要探討的流況包括：平板分別並列於圓柱或方柱前緣，中心線及後緣三種位置的改變，對其下游奉隙流偏向與尾流渦流溢放特性的影響。結果顯示平板置放於方柱後緣位置時，其縫隙流偏向角較位於前緣情況的偏向角度為大；另平板位圓柱後緣情況亦較其位於圓柱前緣位置時的偏向角為大；且隨縫隙寬度增加，平板位於前緣位置情況的偏向角於縫隙寬度約為1.0時，即?保持穩定，而平板位於後緣位置情況則仍持續保持偏向，直到縫隙寬度到達約2W縫隙，偏向持續穩定，險示並列柱體尾流縫隙流的偏向特性會隨平板並列位置的不同，而有顯著的改變。其中以平板與圓柱並列的情況，縫隙流偏向情況較平板與方柱並列的情況更為明顯，且渦流溢放頻率差異甚大及不同，顯示並列圓柱體尾流、縫隙流的偏向特性會隨平板並列位置的不同而不同。

Abstract
The present paper investigates flow characteristics of influence of arrangement position on flow downstream of bluff bodies arranged side by side.The bluff bodies adopted include two-dimensional flat plates,square cylinders,and circular cylinders.
The two-body arrangements are comprised arrangement position of flat plate and square cylinder, flat plate and circular cylinder.Two sets of models are adopted,these being bluff bodies with the same cross-setional dimension but with different vortex shedding frequencies,and bluff bodies with different cross-setional dimension but with the same vortex shedding frequency.
The results demonstrate that the characteristics of flow downstream are significantly related to arrangement position and cross-settional geometry of the bluff body.the gap flow tends to deflect toward the narrow-wake side downstream of the two-body arrangement side by side.The biasing characteristic of the gap flow is relatively unstable as the widths of the wake downstream of each bluff body are nearly the same.

目 錄
中文摘要.……………………………………………………………І.
英文摘要.……………………………………………………………II
致謝..……………………………………………………………….IIV.
目錄.…………………………………………………………………V
圖目錄.………………………………………………………………VI
第一章 緒 論
1-1 研究動機…………………………………………………………..1
1-1-1研究主題.……………………………………………………..1
1-1-2研究背景.……………………………………………………..1
1-1-3此研究之重要性.....…………………………………………..3
1-2文獻回顧..………………………………………………………….3
1-3研究目標...…………………………………………………………4
第二章 研究方法
2-1實驗設備與實驗方法..………..…………………………..……….8
2-2實驗項目與量測內容......……..……………………..….…………15
第三章 研究結果與討論
3-1 平板並列於方柱側面前緣位置.……………………….…………16
3-2 平板並列於方柱側面中心線位置.…………………………….…23
3-3 平板並列於方柱側面後緣位置.……………………………….…28
3-4 平板並列於圓柱側面前緣位置.....…………………………….…35
3-5 平板並列於圓柱側面中心線位置.…………………………….…44
3-6平板並列於圓柱側面後緣位置....…..………………………….…50
3-7平板並列於大圓柱側面中心線位置..………………………….…59
3-8平板並列於大圓柱側面前緣位置......………………………….…62
3-9平板並列於大圓柱側面後緣位置..…………………………….…68
第四章結論與建議
4-1結論.………………………………………………………………..73
4-2建議未來研究方向..……………………………………………….74
參考文獻……………………………………….………….……………75

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