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曾憲中21

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鄭澤明、曾憲中、劉啟煌

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壓電拍片擺動方向與放置位置對具軸向流之鰭柱散熱座之熱傳影響

Effects of Piezoelectric Blade is Moving Orientation and Position on Heat Transfer of the Pin-fin Heat Sink in a Channel with Axial Flow

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2014精密機械與製造科技研討會論文集－PMMT 2014

2014 Precision Machinery and Manufacturing Technology Symposium-PMMT

Keywords：壓電拍片、柱狀鰭片散熱座、強制對流、實驗

Piezoelectric blade,Pin-fin Heat Sink,Forced Convection,Experiment

Abstract：本研究以實驗方法探討壓電拍片對槽道具軸向空氣流之柱狀鰭片散熱座的熱傳影響，採用5x5、7x7、9x9等三種執行排列方柱陣列散熱座為測試塊，裝置於矩形槽道之底壁面上，槽道內有軸向均勻空氣流作為強制冷流，變動參數包刮主流雷諾數、壓電拍片與散熱座之相對擺放位置、實驗結果指出壓電拍片裝置於水平距離散熱座前緣較近之位置、或裝置於垂直距離槽道底壁較遠之位置能有較佳的熱傳效益，整體而言，相對於軸向震盪運動，壓電拍片做橫向震盪的熱傳增益比例會略高一點，而在各式散熱座中，9x9之方注散熱座配合橫向震盪的壓電拍片也會有略高的熱傳增益比例，熱傳增益Nu/Nu0(Nu0為不具壓電拍片時之紐塞數值)會隨主流雷諾數增大而逐趨近於1，在主流雷諾數ReL=1200時，9x9之方柱散熱座於壓電拍片作用下最大之熱傳增益Nu/Nu0超過2。

This work experimentally investigated theeffects of the piezoelectric blade is moving orientation and position on heat transfer of the pin-fin heat sink in a rectangular channel with axial air flow.Three pin-fin heat sinks with 5x5,7x7 and 9x9 in-line pin-fin array,installed at the bottom wall of the channel,were employed as test specimens.There was uniform axial air flow in the channel.The relevant parameters were the Reynolds number of the main flow, the relative position between the piezoelectric blade and the heat sink and the moving orientation of the piezoelectric blade. The results indicate that the shorter the horizontal distance between the piezoelectric blade and the heat sink was or the longer the vertical distance between the piezoelectric blade and the channel’s bottom wall was, the better the total heat transfer enhancement for the transverse-oscillation case was some what higher than that of the axial-oscillation case. Among the present three heat sinks, the 9×9 pin-fin heat sink coupling with the transverse-oscillation piezoelectric blade seemed to have the better heat transfer. The ratio of heat transfer enhancement Nu/Nu0 (NU0 was the Nusselt number for the system without piezoelectric blade) decreased with increasing Reynolds number, and finally reached the unity. At ReL=1200 with the action of the piezoelectric blade, the maximum value of Nu/Nu0 for the 9×9 pin-fin heat sink exceeded 2.

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