一般的工程問題通常使用傳統的正算求解物理量，也就是將已知的條件輸入系統模式求解，稱為正算問題(Direct Problem)。但是實際上存在著許多物理量無法藉由量測計算得到，或是可以藉由其他可測量或可計算的資料，反算得到該物理量，這一類的問題我們稱之為反算問題(Inverse Problem)。
　　反算設計問題也可稱為最佳化設計問題。因反算設計問題的原理是利用目前已知的參數或物理量，對複雜的工程問題作最佳化處理。
　　因此，本論文以實際的散熱模組，使用商業軟體CFD-ACE+ 來建立複雜物理模型的幾何形狀以及其網格，並再利用CFD-ACE+找出鰭片底面最高溫度，以鰭片底面的最高溫度與最後期望下降溫度差作為基礎，利用反算法中的拉凡格式法(Levenberg-Marquardt Method)，針對散熱模組的設計參數進行最佳化預測。然後再利用商用散熱模組，與最佳化的散熱模組進行實驗，最後再利用紅外線熱像儀進行測量，並且與CFD-ACE+ 模擬解得的鰭片厚度表面溫度進行驗證。
　　經過最佳化後，三組散熱模組均能使鰭片底面最高溫度降低，推論結果可能與表面積及流速有相關，在經過實驗驗證後，也證明了模擬與實際上的結果非常相近。

In many practical engineering applications the direct problem is utilized to solve for its physical quantity by substituting the known parameters to the system. In fact, there are many physical values that can not be obtained through direct measurement or calculation in real engineering. However they can be estimated by using inverse design method based on measuring data. These problems are called inverse problems.
Inverse problems are also called optimum design problems. Because Inverse problems are used known parameter or the physical quantity to carried on optimization for the complex engineering problems.
The present study utilized the actual heat sink modules and the general purpose commercial code CFD-ACE+ to find the maximum temperature at fin base and to design the objective function for the optimization problem. A three-dimensional inverse problem in estimating the design variables for actual heat sink modules is solved by using the Levenberg-Marquardt Method (LMM). Finally the original and optimum heat sink modules are carried on the experimental verification.
Results show that the maximum temperature at fin base can be reduced in the optimum heat sink modules and the measured and calculated temperatures on the fin surface are close enough to verify the present design algorithm and calculations.

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