臺灣博碩士論文加值系統

本研究探討平滑及三組內設凸(convex)、凹(concave)配置窩凹(dimple)六邊形管道之詳細熱傳係數(Nu)分佈及壓損係數( f )。本研究檢測雷諾數(Re)之範圍為900-30000，比較三組以凸(convex)、凹(concave)之dimple壁面所排列配置(concave-concave、convex-convex和concave-convex)之六邊形管道熱性能係數；而由於熱性能係數(η)之定義為( /Nu∞)/(f/f∞)1/3，故需進行分析六邊形管道壁面以不同之dimple配置模式，對已發展區之平均熱傳係數( )和管道壓損係數( f )所產生之影響。對任一測試管道而言，雷諾數(Re)為控制參數，並將各測試管道所得之 與f實驗數據，回歸成Re之實驗公式，提供相關業者參考。

關鍵字：六邊形通道、表面窩凹、熱傳強化

Measurements of detailed Nusselt number (Nu) distributions and
pressure drop coefficients ( f ) for four hexagonal ducts with smooth and
dimpled walls are performed to comparatively examine the thermal
performances of three sets of dimpled walls with concave-concave,
convex-convex and concave-convex configurations at Reynolds numbers
(Re) in the range of 900-30000. A set of selected experimental data
illustrates the influences of dimple configuration and Re on the detailed
Nu distributions, the area averaged Nu over developed flow region ( Nu )
and the pressure drop coefficients. Relative enhancements of Nu and f
from the smooth-walled references (Nu

目 錄

謝誌………………………………………………………………… I

中文摘要…………………………………………………………… II

英文摘要…………………………………………………………… III

圖目錄……………………………………………………………… IV

符號說明…………………………………………………………… V


第一章、前言…………………………………………………….… 1

1-1 應用背景…………………………………………………… 1

1-2 文獻回顧…………………………………………………… 2

1-3研究動機與目標…………………………………………… 6

1-4 論文架構…………………………………………………… 7


第二章、實驗設備與方法…………………………………….…… 9

2-1實驗流程………………………………………………….... 9

2-2實驗設備與熱傳測試件……………….…………………... 11

2-3實驗步驟…………….……………………………………... 16

2-3-1 熱傳與壓損實驗步驟…...…………………………. 16

2-3-2 熱損失實驗步驟…………...………………………. 18

2-4實驗誤差分析……………………………………………... 20


第三章、實驗結果與討論………………………………………….. 22

3-1六邊形窩凹管道熱傳研究………………………………... 22

3-2六邊形窩凹管道壓損研究………………………………... 30

3-3六邊形窩凹管道熱性能分析……………………………... 33


第四章、結論與建議………………………………………………. 35


參考文獻……………………………………………………………. 38

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