臺灣博碩士論文加值系統

衝擊冷卻有局部高熱傳的優點，已被廣泛用於工業界，如工業乾燥、金屬與玻璃退火、氣渦輪葉片冷卻、電子散熱等。多孔材在熱流的應用也日益受到重視。衝擊冷卻與多孔材的結合是值得探討的問題。
本研究利用加熱片配合熱偶量測方法以及暫態液晶實驗方法探討半圓球凹面有、無貼附具中心集孔多孔材的衝擊熱傳，也以MatLab語言成功的改善了液晶技術影像處理與數據化約程式。本實驗探討的參數包含雷諾數、噴嘴到目標板距離、相對曲率以及凹面是否有貼附具中心集流孔之多孔材等。
實驗結果顯示，加熱片與熱偶的量測方法雖然數據不多，但是可以延伸到整個半球範圍；無論有無貼附多孔材，雷諾數的增加一般可以提升紐賽數，但是太高的雷諾數會使得停滯區的紐賽數下降；當凹面有覆蓋多孔材時，停滯區的紐賽數分佈值隨著噴嘴到目標板的距離的增加而降低，但是遠處的紐賽數卻有不同的變化趨勢；液晶實驗方法雖然可以得到詳細紐賽數分佈數據，但是此方法會受到觀察角度的影響。

Jet impingement cooling has the advantage of localized high heat transfer rate. It has been widely applied to industries such as industrial drying, metal and glass annealing, gas turbine blade cooling, and electronics cooling. Porous material in thermal/fluid applications is also attracting people's attention. The combination of impingement heat transfer and porous material is worthy of investigation.
This thesis applies two experimental methods, heating foil with thermocouple measurement and transient liquid crystal technique, to the investigation of jet impingement heat transfer onto a semi-spherical concave surface covered with or without porous material with a center trapping hole. A new image processing and data acquisition program has also been successfully developed in this research for the improvement of liquid crystal technique. The investigated parameters of the research include Reynolds number, nozzle-to-plate distance, relative curvature, and the concave surface with or without porous material.
Experimental results show the following. Although the measuring method with heating foil and thermocouples does not give many data points, the measurement can be extended to the whole semi-sphere. No matter the concave surface is covered by the porous material or not, an increase of Reynolds number (Re) usually increases Nusselt number (Nu). However, too high Reynolds number may cause the stagnation Nusselt number to decrease. With the coverage of porous material, stagnation Nusselt number decreases with an increase of the nozzle-to-plate distance, but the Nu in the far field may vary in different trends. Although liquid crystal technique may provide detailed Nu distribution, this method may subject to influence of viewing angles.

簽名頁---------------------------------------------------ii
中文摘要---------------------------------------------------iii
ABSTRACT---------------------------------------------------iv
誌謝---------------------------------------------------vi
目錄---------------------------------------------------vii
圖目錄---------------------------------------------------x
表目錄---------------------------------------------------xvi
符號說明---------------------------------------------------xvii

第一章 緒論---------------------------------------------------1
1.1 研究背景---------------------------------------------------1
1.2 研究目的---------------------------------------------------2
1.3 文獻回顧---------------------------------------------------3
第二章 實驗系統與研究方法---------------------------------------------------7
2.1實驗系統概述與設計---------------------------------------------------7
2.1.1實驗載台---------------------------------------------------7
2.1.2光源模組---------------------------------------------------8
2.1.3熱風產生系統 ---------------------------------------------------9
2.1.4氣體冷卻裝置 ---------------------------------------------------9
2.1.5氣體快速切換模組---------------------------------------------------10
2.1.6實驗模型---------------------------------------------------10
2.2 DAQ組件---------------------------------------------------11
2.2.1影像擷取系統--------------------------------------------------- 12
2.2.2溫度資料擷取系統---------------------------------------------------12
2.2.3壓力量測系統--------------------------------------------------- 13
2.2.4流量量測系統--------------------------------------------------- 13
2.3實驗案例與實驗程序---------------------------------------------------14
2.3.1系統檢查調整階段---------------------------------------------------14
2.3.2實驗測試階段--------------------------------------------------- 15
2.3.3數據化約階段 ---------------------------------------------------16
第三章 結果與討論--------------------------------------------------- 18
3.1熱偶量測實驗結果---------------------------------------------------18
3.2液晶技術與熱偶量測之比較---------------------------------------------------19
3.3凹面無覆蓋多孔材的液晶實驗結果---------------------------------------------------20
3.4凹面有覆蓋多孔材的液晶實驗結果---------------------------------------------------21
3.5凹面貼附多孔材的影響---------------------------------------------------22
第四章 結論---------------------------------------------------23
參考文獻---------------------------------------------------25
附錄 1 多孔材半圓&半球加工程序---------------------------------------------------61
附錄 2 流量計校正計算---------------------------------------------------64
附錄 3 使用攝影機擷取顯色狀況之Matlab程式---------------------------------------------------65
附錄 4 局部紐賽數數據化約原始程式碼---------------------------------------------------66


圖目錄

圖 2.1：實驗系統示意圖---------------------------------------------------31
圖 2.2：初期實驗載台---------------------------------------------------32
圖 2.3：調整光原後的實驗載台---------------------------------------------------33
圖 2.4：熱風產生系統&氣體冷卻裝置---------------------------------------------------34
圖 2.5：氣體快速切換模組設計圖---------------------------------------------------34
圖 2.6：氣體快速切換模組實體圖---------------------------------------------------35
圖 2.7：熱偶實驗用模型示意圖[26]---------------------------------------------------35
圖 2.8：熱偶實驗用模型---------------------------------------------------36
圖 2.9：液晶實驗用半圓測試塊設計圖與照片---------------------------------------------------36
圖 2.10：實驗用有中心集流孔多孔鋁---------------------------------------------------37
圖 2.11：100-HC數據收集盒 ---------------------------------------------------37
圖 2.12：差壓傳送器---------------------------------------------------38
圖 2.13：浮子流量計---------------------------------------------------39
圖 2.14：R28C1W熱像液晶校正之顯色狀況。---------------------------------------------------39
圖 2.15：偶溫度分布曲線---------------------------------------------------40
圖 2.16：R28C1W熱像液晶校正線---------------------------------------------------41
圖 2.17：暫態實驗影片的張數時間與當時音效檔案之操作介面---------------------------------------------------42
圖 2.18：暫態實驗之音頻訊號---------------------------------------------------42
圖 3.1：半圓球凹面有、無覆蓋具中心集流孔多孔材的熱偶量測實驗結果(H/DJ = 6) [26]---------------------------------43
圖 3.2：半圓球凹面有、無覆蓋具中心集流孔多孔材噴嘴至目標板距離之影響的熱偶量測實驗結果(RE=12400) [26]-------------44
圖 3.3：熱偶與液晶實驗比較 (RE = 12400，H/DJ = 6，無多孔材)---------------------------------------------------45
圖 3.4：熱偶與液晶實驗比較 (RE = 17900，H/DJ = 6，無多孔材)---------------------------------------------------46
圖 3.5：熱偶與液晶實驗比較 (RE = 23000，H/DJ = 6，無多孔材)---------------------------------------------------47
圖 3.6：液晶暫態實驗過程在時間(A) 3秒與(B) 15秒的顯色情形(RE = 12400，H/DJ = 6，無多孔材)-----------------------48
圖 3.7：熱偶與液晶實驗比較 (RE = 12400，H/DJ = 6，有多孔材) 49
圖 3.8：液晶暫態實驗過程在時間(A) 3秒與(B) 15秒的顯色情形(RE = 12400，H/DJ = 6，有多孔材)-----------------------50
圖 3.9：典型的原始數據與曲線適配結果(RE = 23000，H/DJ = 6，無多孔材)----------------------------------51
圖 3.10：雷諾數對紐賽數的影響(DJ=10MM，H/DJ = 6，無多孔材)-------------------------------------------52
圖 3.11：噴嘴到目標板的距離(H/DJ)對紐賽數的影響(RE = 12400，無多孔材)---------------------------------53
圖 3.12：噴嘴到目標板的距離(H/DJ)對紐賽數的影響(RE = 23000，無多孔材)---------------------------------54
圖 3.13：相對曲率對紐賽數的影響(RE = 23000，無多孔材)------------------------------------------------55
圖 3.14：雷諾數對紐賽數的影響(DJ=10MM，H/DJ = 6，有多孔材)-------------------------------------------56
圖 3.15：噴嘴到目標板的距離(H/DJ)對紐賽數的影響(RE = 23000，有多孔材)---------------------------------57
圖 3.16：相對曲率對紐賽數的影響(RE = 23000，有多孔材)-------------------------------------------58
圖 3.17：凹面有無多孔材貼附的影響(RE = 12400)---------------------------------------------------59
圖 3.18：凹面有無多孔材貼附的影響(RE = 23000)---------------------------------------------------60


表目錄

表 2.1：實驗案例總表---------------------------------------------------30

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