Soret and Dufour Effects on Double-Diffusive Mixed Convection From a Vertical Wedge in Porous Media with Constant Wall Heat and Mass Fluxes

索瑞特與杜佛效應對多孔物質內承受固定熱通量與質通量垂直楔形體雙重擴散混合對流之影響

鄭慶陽(Ching-Yang Cheng)

《中國機械工程學刊》 33卷2期 (2012/04) Pp. 141-149

https://doi.org/10.29979/JCSME.201204.0006

摘要

本文研究索瑞特與杜佛效應對多孔物質內承受固定熱通量與質通量垂直向下楔形體雙重擴散混合對流之影響。進行坐標轉換後再以三次樣線配置法求解所得之非相似方程式。研究索瑞特參數、杜佛參數、楔形角參數、路易士數與浮力比對熱傳與質傳特性之影響。結果顯示，增加杜佛參數會增加局部表面溫度。而且增加索瑞特參數會增加局部表面濃度。對強迫對流與以強迫對流為主之混合對流，增加楔形角參數會增加局部表面溫度與濃度。對自然對流與以自然對流為主之混合對流，增加楔形角參數不會影響局部表面溫度與濃度。

並列摘要

This work studies the Soret and Dufour effects on the double-diffusive mixed convection over a downward-pointing vertical wedge in a porous medium with constant wall heat and mass fluxes. A suitable coordinate transformation is performed, and the obtained nonsimilar equations are then solved by cubic spline collocation method. The effects of the Soret parameter, Dufour parameter, wedge angle parameter, mixed convection variable, Lewis number, and buoyancy ratio on the heat and mass transfer characteristics has been studied. Results show that the local surface temperature is found to increase when the Dufour parameter is increased. Moreover, an increase in the Soret number leads to an increase in the local surface concentration. As the wedge angle parameter is increased, the local surface temperature and the local surface concentration increases for forced convection and forced-convection-dominated mixed convection. The wedge angle parameter is insignificant for natural convection or natural-convection-dominated mixed convection.

並列關鍵字

mixed convection ； double diffusion ； vertical wedge ； porous medium ； Soret effect ； Dufour effect