臺灣博碩士論文加值系統

摘要
本文利用FLUENT套裝軟體以數值模擬方式進行，針對於二維層流流場中並排擺置之雙圓柱結構，探討圓柱間距比對流場結構及熱傳現象之影響。本文分析之圓柱間距比P/d為由2.0縮小至1.1，於雷諾數為1000，而圓柱表面溫度為350K與自由流溫度為300K時，經由觀察結構體下游流域所形成之流場變化，及間隙流流速之變化，探討雙圓柱結構間之流場相互干擾現象對於圓柱表面之熱傳影響。
由分析結果得知，間距比P/d由2.0縮小至1.5時，間隙流之偏向現象逐漸明顯，寬窄尾流區寬度之差距亦逐漸加大，且間隙流流速會隨間距比之縮小而逐漸加快，進而從圓柱上帶走更多熱量增進熱傳效果，使得兩圓柱之平均鈕塞數逐漸增大；若間距比小於1.5時，間隙流之偏向現象更為明顯，但間隙流流速卻反而呈現逐漸減慢之現象，此時兩圓柱之平均鈕塞數亦隨之逐漸降低；而於間距比P/d＝1.2時，由於窄域尾流之寬度急遽縮減，其對圓柱熱傳之助益勝於間隙流流速持續降低之影響，使得具窄域尾流之圓柱其平均鈕塞數出現上升之現象。

Abstract
The objective of this research is to investigate the flow interference and heat transfer phenomenon of a pair of identical circular cylinder, arranged side-by side in cross flow with various pitch ratios at Reynolds number of 1000. The analysis was performed by using the FLUENT software, the flow and temperature fields, jet deflection, flow interference, and the local and the average Nusselt numbers were studied in this research.
It is observed that as the pitch ratios between 2.0 and 1.5, the jet emerging between cylinders deflects and forms one wide and one narrow wakes behind the cylinders. The gap flow velocity increases as the pitch ratio decreases and consequently increases the average Nusselt number of the cylinders. As the pitch ratio less than 1.5, the jet deflection is more severe and the gap flow velocity starts to decrease slowly. This results to reduce the average Nusselt number of the cylinders. Due to the reduction of the narrow wake width, the average Nusselt number of the cylinder with narrow wake shows an uprising tendency for the pitch ration less than 1.2.

目錄
摘要.......................................................I
英文摘要..................................................II
目錄.....................................................III
圖目錄....................................................IV
符號說明.................................................VII
第一章 緒論................................................1
第二章 文獻回顧............................................2
第三章 研究方法及進行步驟..................................8
3.1分析模型與基本假設......................................8
3.2統御方程式及邊界條件....................................9
3.3數值模擬流程...........................................10
第四章 結果與討論.........................................14
第五章 結論...............................................25
參考文獻..................................................27

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