臺灣博碩士論文加值系統

隨著時代進步，許多產品均朝向電子化發展，也使得現今有關於電子產業的散熱技術格外顯的重要，在電子散熱的方式中，最方便且最具經濟性的散熱方式即為使用鰭片散熱器，本研究主要使用質點顯像測速系統，藉非接觸式方式量測板鰭式散熱器以及鍵鰭式散熱器之鰭片內部流道各截面中心流場結構以及流場分佈情形，實驗時以不同厚度的散熱風扇作吹入與抽出兩種流動方式，並依據實際電腦之散熱風扇工作情形，改變風扇轉速之測試條件作為探討。
以板鰭式而言，量測結果發現此裝置之強制對流下散熱方式，會因受到風扇馬達遮斷流路之影響，造成鰭片內流場結構在各截面中都呈現不同情形。比較吹入及抽出的兩種風扇作動方式，前者產生渦流之截面數量會較後者少且渦流結構較不完整；實驗中採用不同尺寸之散熱風扇，因風扇為葉片旋轉方式作動產生氣流，而在出風口兩側會有不同的風量情形，在產生渦流的區域會因流量增加而使結構更加明顯。
此外，吹入式可造成鰭片內流場的流動方式加速向散熱器外側流動，且不易受到風扇馬達遮蔽所影響，以抽出式之散熱方式時會隨著散熱鰭片的截面由外往內觀測可量測出不同截斷面受到風扇馬達軸心之邊界影響，產生的渦流結構使空氣流體不易排出。在配合於相同實驗條件下操作之紅外線熱像儀量測，亦能驗證對板鰭式散熱器而言，由上方吹入冷氣流的風扇作動方式較抽出有較佳的散熱效果。而鍵鰭式散熱器有別於板鰭式之幾何造型，在相同之截面下量測內流場時，發生渦流使流體滯留的現象已不明顯。經由質點顯像測速裝置可量測出各截面進出口之速度分佈，再配合各截面的進出口幾何尺寸，能夠估算出各斷面所流進的流量，了解到因風扇的幾何造型對於進入鰭片散熱器的流量有極大之影響。

As technology advances, many products move towards electrification. Heat transfer is very important in the electronic industry. The finned heat sink is the most convenient and economic way of cooling. This research uses the Particle Image Velocimetry System－a non-invasive method that measures the interior flow patterns of the plate-finned and pin-finned heat sink. Different fan sizes were used along with two different flow types; for example, blow-out and draw-in. By changing the rotation speed of the fan, we can see the impact using a computer cooling fan.

The test results using the plate-finned heat sink showed that it was influenced by the axis of the fan. Different interior flow patterns appeared in each section. Comparing the draw-in and blow-out airflow of a fan, the vortex produced is less when the air is drawn in than when the air is blown out. Because both sides of the outlet have different air volumes, using different cooling fan sizes produces more obvious results.

The draw-in and blow-out air flows of the fan produces different results. The study found a large vortex near the center of the base for when using the blow-out function. To improve the cooling effects, the cold air draw-in the plate-fin heat sink is the best choice. This conclusion is also confirmed by infrared thermography. Because the geometry and size of the pin-finned heat sink is different from the plate-finned heat sink, the vortex was not obvious when measured under the same conditions. The PIV system was used to produce a diagram of the import and export velocity contours. This information was used to estimate the flow volumes for each section by comparing to the inlet size. The geometry of the fan has a large influence on the entering air flow volumes.

目 次
中文摘要............................................................................................................................i
英文摘要...........................................................................................................................ii
致謝..................................................................................................................................iv
目錄...................................................................................................................................v
表目錄.............................................................................................................................vii
圖目錄............................................................................................................................viii
符號說明...........................................................................................................................x
第一章 緒論.................................................................................................1
1.1 前言............................................................................................................................1
1.2 研究目的....................................................................................................................1
1.3文獻回顧.....................................................................................................................2
第二章 質點顯像測速系統之原理.............................................................6
2.1 影像分析之計算........................................................................................................6
2.2 實驗前置作業............................................................................................................7
2.2.1 四分之一法則................................................................................................8
2.2.2 動力速度範圍................................................................................................8
2.2.3 動力空間範圍..............................................................................................10
第三章 實驗儀器設備.............................................................................................12
3.1實驗儀器....................................................................................................................12
3.2質點顯像測速系統（PIV System）.............................................................................12
3.3油霧質點產生器........................................................................................................14
3.4測試件製作................................................................................................................15
3.4.1 板鰭式散熱器（測試件A）...........................................................................15
3.4.2 鍵鰭式散熱器（測試件B）..........................................................................16
3.4.3 流場觀測之測試箱體...................................................................................16
3.5 風扇轉速之選用......................................................................................................17
3.6 風扇轉速測定..........................................................................................................17

第四章 結果與討論..................................................................................................26
4.1 測試件A(板鰭式散熱器)實驗結果........................................................................26
4.1.1 以case1風扇吹入........................................................................................26
4.1.2以case1風扇抽出.........................................................................................28
4.2 以Case2風扇觀察不同截面之流場變化...............................................................30
4.2.1以風扇抽出散熱方式下觀察各截面流場....................................................30
4.2.2以風扇吹入散熱方式下觀察各截面流場....................................................31
4.2.3 EE截面在不同風扇轉速之流場變化..........................................................31
1.以風扇抽出方式觀察不同轉速各截面流場.................................................31
2.以風扇吹入方式觀察不同轉速各截面流場.................................................32
4.3 不同風扇作動下之比較..........................................................................................32
4.3.1 以抽出式(Blow-Out)比較Case1和Case2風扇.........................................32
4.3.2 以吹入式(Draw-In)比較Case1和Case2風扇..........................................33
4.4 散熱鰭片各截面流量之估算..................................................................................33
4.4.1 各截面受風扇馬達軸心遮蔽對流量之影響以抽出式(Blow-Out)...........33
4.4.2 各截面受風扇馬達軸心遮蔽對流量之影響以吹入式(Draw-In)..............34
4.4.3 風扇轉速對於流量之影響..........................................................................34
第五章 結論與未來工作............................................................................80
5.1結論............................................................................................................................80
5.1.1板鰭式散熱器................................................................................................80
5.2 未來工作..................................................................................................................81
參考文獻......................................................................................................83
附錄一..........................................................................................................87
個人簡歷......................................................................................................89

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