本文以三維CFD軟體搭配實驗及逆向方法研究垂直抽風板鰭管式熱交換器於矩形流道的混合對流熱流特性。探討具溝槽鰭片於不同入口流速及鰭片間距之影響，因此設計方形鰭片、雙溝槽H型鰭片及單溝槽U型鰭片。由於流體流經鰭片時會產生複雜的三維流動，鰭片上不同區域熱傳系數不盡相同，故將鰭片切割為八個子區域，搭配逆向方法及最小平方法快速找尋各個子區域之熱傳系數預估值，並以此計算鰭片表面之Q及h̅預估值。另一方面，本研究使用CFD軟體模擬取得熱流特性結果及各種後處理視圖，利用實驗數據及逆向方法之Q及h̅預估值驗證紊流模式選用及網格劃分之適當性。結果指出，垂直抽風板鰭管式熱交換器於入口流速為1m/s ~ 5m/s時，RNG k-ε為最適當的流動模式；入口流速對具溝槽鰭片之熱傳增幅有決定性之影響；U型鰭片相較H型鰭片有較佳的熱傳表現。

This study uses three-dimensional computational fluid dynamics(CFD) numerical simulation along with inverse method and experimental temperature data to investigate the mixed convection heat transfer of grooved plate finned tube heat exchanger in rectangular tunnel. The effects of inlet velocity Va and fin spacing S are investigated. Three kinds of fins including plate fin, H-type fin and U-type fin are designed for this study. The inverse method in conjunction with finite difference method and least-squares scheme are applied to predict the heat transfer characteristics. On the other hand, the temperature contour, streamline and heat characteristics are determined by CFD. In order to obtain more accurate simulation results, the selection of flow models and mesh system must be tested by the experimental and inverse results. It is found that RNG k-ε is the most suitable flow model for present work. U-type fin has better performance in heat transfer than H-type fin.

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