散熱器外型之最佳化設計

Abstract

為探討散熱器基座外型對散熱功率的影響，本文利用Boundary Element Method (BEM)與Conjugate Gradient Method (CGM) 的數值方法對一二維之散熱器剖面形狀進行分析。其中BEM可針對任意幾何外型計算出其所對應之溫度場而無格點分割的問題。CGM則結合最小均方法之技巧，應用在逆運算問題時，其在計算較多參數的情況下仍能得到快速的收斂。在操作條件為目標溫度分佈、邊界條件的情況下計算出各種測試範圍所對應之結果。我們認為1.初始猜測值2.目標溫度分佈對最佳化設計結果有很大的影響。然而為能符合最佳化設計的要求，初始猜測值的適合性及目標溫度分佈的合理性是我們所必須考量的。最後本文建立了一套散熱器最佳化的設計機制，並透過此機制在考量誤差函數內各項之權值比重及邊界條件對其之影響而求得最佳設計之結果。

To investigate the influence of heat efficiency for the shape of a heat sink base, an inverse analysis is performed to estimate optimal shape of a heat sink base by using the boundary element method (BEM) and conjugate gradient method (CGM) with the 2-D cross-section of the heat sink. The BEM is used to calculate the direct, sensitivity and adjoint problem due to its characteristics of easily-handling the problem considered here. One of the advantage of using CGM lies in that it can easily handle problems having hung number unknown parameters and it converges very fast. An analysis model of the optimal shape of a heat sink base is established by considering the influence of the initial guess and the desired temperature distributions. By using the optimal analysis model, we successfully design the optimal shape of a heat sink base with considering the proportion of the temperature to the cross-section area.