本文使用新穎之逆向計算流體力學方法結合實驗溫度數據及最小平方法研究空腔之熱壁上具有一水平鰭片之暫態自然對流熱傳特徵。透過比較不同流動模型所獲得之流場分布圖、均方根誤差、熱壁之熱傳係數與最大速度，選定各時段之合適流動模型，並求得溫度分布、速度流線分布、熱傳率、熱傳係數、瑞利數隨時間之變化。
由結果可知，在層流階段之合適模型為層流模型，過渡流階段之合適模型為零方程式模型，紊流階段之合適模型為標準k-ε模型。層流轉為過渡流與過渡流轉為紊流之瑞利數分別為1.46×〖10〗^6與6.97×〖10〗^6，其數值與參考文獻相近，故本文結果具有一定的準確度。此外，本文求得之熱壁的紐森數與最大速度皆與對應之經驗公式具有良好的一致性。

In this paper, the novel transient inverse computation fluid dynamics (CFD) method along with experimental temperature data is applied to investigate three-dimensional natural convection heat transfer in a cubic cavity with a horizontal fin on a vertical hot wall. The heat transfer rate, appropriate flow models, heat transfer coefficient, Rayleigh number ranges for different flow regimes, and the temperature and velocity distributions are predicted at selected time points.
The results show that the appropriate flow model for the laminar, transitional, and turbulent flow regimes are the laminar model, zero-equation model, and standard k-ε model, respectively. the Rayleigh number for the laminar to transitional flow and transitional to turbulent flow are 1.46×〖10〗^6 and 6.97×〖10〗^6, respectively. This critical Rayleigh number is consistent with related paper’s result. Thus, the present estimates are accurate. Furthermore, the estimates of Nu_h and V_max are in good agreement with the proposed correlation.

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