摘要
本文使用田口法探討空氣衝擊冷卻下鰭片散熱器最佳化的數值模擬。在四個設計參數且每個參數具有三種水準之下，本文選用 的直交表來執行測試。數值計算的方法上，是以控制體積法為基礎，並配合有限差分及冪次法則在正交、非等間距的交錯式格點上將各統御方程式離散成差分方程式，並且以SIMPLEC法來求解動量方程式中壓力項與速度項的耦合問題。對於紊流的運動以及結構則是以 雙方程紊流模式來描述。
文中討論的參數有：雷諾數(Re=10000~25000)，鰭片間距a (2mm~ 6.4mm)，鰭片間距b (2mm~6.4mm)，鰭片間距c (2mm~6.4mm)。本文中主要探討的是鰭片間的距離和鰭片高度對散熱器熱阻的影響，並且應用田口法來找尋最佳的設計參數組合。其結果顯示從散熱器中心往外到邊緣的鰭片間距應由小逐漸變大，而鰭片高度則是越高越好。因此，最佳組為 。此外，設計參數對熱阻的影響由大到小為：間距a，鰭片高度H，間距c與間距b。

關鍵字：衝擊冷卻、最佳化、鰭片散熱器、田口法、紊流

Abstract
This study presents the numerical simulation of optimum pin-fin heat sink with air impinging cooling by using Taguchi method. orthogonal array is selected as a plan for the four design-parameters with three levels.The governing equations are discretized by using control-volume-based-finite -difference method with power-law scheme on an orthogonal non-uniform staggered grid. The coupling of the velocity and the pressure terms of momentum equations are solved by SIMPLEC algorithm. The two-equations turbulence model is employed to describe the turbulent structure and behavior.
The parameters studied include Reynolds number (Re =10000~25000), inter-fin spacing a(2mm~6.4mm), inter-fin spacing b(2mm~6.4mm)，inter-fin spacing c(2mm~6.4mm).The objective of this study is to examine the effects of the fin spacings and fin height on the thermal resistance and then find the optimum group by using Taguchi method. It’s found that the fin spacings from center to edge of the heat sink should be gradually extended, and the fin’s height is the longer the better. Then, the optimum group is . In addition, the ranks of the design parameters on thermal resistance from maximum to minimum are spacing a, fin height, spacing c, spacing b.

Keywords：impinging cooling, optimum, pin-fin heat sink, Taguchi method, turbulence

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