緻密性堆疊型散熱鰭片在強制對流下之熱流分析

Experimental Investigation of Thermal-Hydraulic Performance of the Compact Stack Fin Heat Sinks for Forced Convection

江慶銘(Ching-Ming Chiang)

指導教授 ： 林育才

元智大學/工程學院/機械工程學系/碩士(2006年)

摘要

本論文為研究複合型、三角翼型、百葉窗型、平板型及裂口型散熱鰭片的熱流性能。比較鰭片的熱傳性能和鰭片間距效應的關聯性。測試的結果指出增強型鰭片如百葉窗型鰭片操作在較高的正向速度與較大的鰭片間距之條件下其性能優於平板型鰭片。結果也發現，百葉窗型鰭片的熱傳性能更勝於其它型式的鰭片，但伴隨著較高的壓降。測試的結果也顯示熱傳性能在較低的雷諾數或較小的鰭片間距下，將會有明顯地降低；亦即所謂的“最大值”庫爾本因子的現象。此現象可應用至所有的鰭片型式。藉由仔細地檢查測試結果，可斷定此現象關係著發展中與完全發展流的特性。事實上，最大值約發生在Gz=10，此值可區分流體為完全發展流或為發展流。為了得知所測試的鰭片之熱傳性能，將採用VG-1及FG-3兩種法則作爲評估。

關鍵字

複合型 ； 三角翼型 ； 百葉窗型 ； 裂口型 ； 庫爾本因子 ； 葛雷茲數

並列摘要

This study presents the thermal-hydraulic performance of heat sinks having complex, delta wing, louver, plain, and slit fin patterns. Comparison of the associated heat transfer performance and the effect of fin pitch are made. Test results indicate that the enhanced fin pattern, like louver fin, is preferable to the plain fin geometry when operating at a higher frontal velocity or at a larger fin pitch. It is also found that the heat transfer performance of louver fins is better than that of other fins at the expense of higher pressure drops. Test results also reveal a significant drop of heat transfer performance at a lower Reynolds number, or at a smaller fin pitch, or the so-called “maximum” phenomenon of Colburn factor. This is applicable to all the tested geometries. By carefully examining the test results, we conclude that this phenomenon is related to the developing/fully developed flow characteristics. In fact, the maximum point occurs roughly at Gz=10 where fully developed and developing flows are separated. For performance evaluation of the tested heat sinks, comparisons are made subject to the VG-1 and FG-3 criteria.

並列關鍵字

complex ； delta wing ； louver ； slit ； Colburn factor ； Graetz number

參考文獻

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