- 學位論文
風扇流體速度分佈對於鰭片散熱性能的影響
Effects of Fluid Velocity Distributions from Fan on Heat Transfer Performance
摘要
中文摘要 本文基本概念為在熱源上加裝散熱鰭片，以風扇吹出之流體衝擊鰭片以達到散熱效果，一般的散熱器熱源通常都是在其正下方，而風扇因軸承關係，所以吹出之流體形式為非均勻流體，因此造成在最急需散熱處因為風扇軸承的關係卻只有整體的最小風量來散熱，有鑑於此，故想探討非均勻流體與均勻流體在不同散熱鰭片裡的熱效率情形。 本文是使用Icepak計算流體力學套裝軟體，模擬研究熱源在不同鰭片幾何尺寸下，經由一般風扇吹出的流體形式與均勻流體衝擊鰭片之間的熱效率比較。鰭片採用6片之板狀鰭片、7片之板狀鰭片、6×6陣列鰭片、7×7陣列鰭片這四種類型，散熱鰭片底部尺寸固定大小為L×L=80mm×80mm，鰭片底部厚度δ也固定為8mm，而鰭片寬度分別取6mm、7mm、8mm、9mm、10mm，高度分別取40mm、60mm、80mm。在熱源方面，模擬CPU大小尺寸約為31.5mm×31.5mm，發熱瓦數設為80W，固定流體流量為 (45CFM)。 結果顯示在固定流量下，均勻流體衝擊鰭片的確比非均勻流體衝擊鰭片的散熱情形要來的好，而且在不同幾何尺寸的鰭片下，其散熱表現也不相同。
並列摘要
ABSTRACT The main purpose of this study is to build heat sink above heat source, The fluid type from fan is to impinge heat sink to reach thermal dissipation effect. The heat source is usually equipped under the heat sink. Because of the fan hub, the fluid type is non-uniform flow. It only has minimum flow to impinge the place that need thermal dissipation urgently. In view of this, I want to discuss the thermal efficiency of heating dissipation in different heat sinks between non-uniform flow and uniform flow. This article use Icepak software CFD package to simulate the thermal efficiency in different flow types and heat sinks. The heat sink adopt four types, 6 parallel plate heat sink, 7 parallel plate heat sink, 6×6 array heat sink, 7×7 array heat sink, The dimension of heat sink base is 80mm×80mm, thickness is 8mm, and fin width is 6mm, 7mm, 8mm, 9mm, 10mm, fin height is 40mm, 60mm, 80mm. The dimension of hot spot is 31.5mm×31.5mm, the power is 80w, flow rate is (45CFM). Result show that under the fixed flow rate, it has better thermal efficiency for using non-uniform flow than using uniform flow to impinging heat sink. It also has different thermal character in different heat sink geometry.