Effects of thermal radiation on natural convection heat and moisture transfer in rectangular enclosures partially filled with hygroscopic porous medium

被引:0
作者
Wang, Yuancheng [1 ,2 ]
Yang, Kaimin [1 ]
Yang, Jun [1 ]
机构
[1] College of Thermal Energy Engineering, Shandong Jianzhu University, Jinan, 250101, Shandong
[2] Key Laboratory of Renewable Energy Utilization Technologies in Buildings of the National Education Ministry, Jinan, 250101, Shandong
来源
Huagong Xuebao/CIESC Journal | 2015年 / 66卷
基金
中国国家自然科学基金;
关键词
Enclosure; Heat and moisture transfer; Hygroscopic porous medium; Natural convection; Surface thermal radiation;
D O I
10.11949/j.issn.0438-1157.20150267
中图分类号
学科分类号
摘要
This paper deals with the effects of thermal radiation on natural convection heat and moisture transfer in rectangular enclosures partially filled with hygroscopic porous medium. The governing equations for the momentum, heat and moisture transfer were solved by the finite element method. The radiative heat transfer is calculated by making use of the radiosity of the surfaces that assumed to be grey. Comparisons with experimental and numerical results in the literature have been carried out. Effects of thermal radiation, Rayleigh number, Darcy number and a ratio, Rk, of thermal conductivity on natural convection, heat and moisture transfer in both free fluid and hygroscopic porous medium were analysed. It was found that the surface thermal radiation significantly alters the distribution of the temperature in rectangular enclosures and moisture content of hygroscopic porous medium even if the given emissivity is quite small, but there are no remarkable temperature and moisture content changes with the increase of emissivity from 0.5 to 1.0. The mean temperature at the interface and the moisture content in hygroscopic porous medium decrease with the increase of Ra. The Nuc on the side walls in the free flow and porous medium regions increase with the increase of Ra. The temperature and moisture content distributions change little in porous medium during heat and moisture content transfer with the increase of Rk while the mean convective Nusselt number on the side walls of rectangular enclosures changes very little in a range of given Da and Rk. ©, 2015, Chemical Industry Press. All right reserved.
引用
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页码:130 / 137
页数:7
相关论文
共 20 条
[1]  
de Davis G.V., Natural convection of air in a square cavity: A benchmark numerical solution, International Journal for Numerical Methods in Fluids, 3, pp. 249-264, (1983)
[2]  
Markatos N.C., Pericleous K.A., Laminar and turbulent natural convection in an enclosed cavity, International Journal of Heat and Mass Transfer, 27, pp. 755-772, (1984)
[3]  
Henkes R.A.W.M., Hoogendoorn C.J., Scaling of the laminar natural convection flow in a heated square cavity, International Journal of Heat and Mass Transfer, 36, pp. 2913-2923, (1992)
[4]  
Orazio A.D., Coreione M., Celata G.P., Application to natural convection enclosed flows of a Lattice Boltzmann BGK model coupled with a general purpose thermal boundary condition, International Journal of Thermal Sciences, 43, pp. 575-586, (2004)
[5]  
Balaji C., Venkateshan S.P., Interaction of surface radiation with free convection in a square cavity, International Journal of Heat and Fluid Flow, 14, pp. 260-267, (1993)
[6]  
Akiyama M., Chong Q.P., Numerical analysis of natural convection with surface radiation in a square enclosure, Numerical Heat Transfer, Part A, 31, pp. 419-433, (1997)
[7]  
Ramesh N., Venkateshan P., Effect of surface radiation on natural convection in a square enclosure, Journal of Thermophysics and Heat Transfer, 13, pp. 299-301, (1999)
[8]  
Ridouane E.H., Hasaoui M., Amahmid A., Raji A., Interaction between natural convection and radiation in a square cavity heated from below, Numerical Heat Transfer, Part A, 45, pp. 289-311, (2004)
[9]  
Bouali H., Mezrhab A., Amaoui H., Bouzidi M., Radiation-natural convection heat transfer in an inclined rectangular enclosure, International Journal of Thermal Sciences, 45, pp. 553-566, (2006)
[10]  
Nishimura T., Takumi T., Shiraisi M., Kawamura Y., Ozoe H., Numerical analysis of natural convection in a rectangular enclosure horizontally divided into fluid and porous regions, International Journal of Heat and Mass Transfer, 29, pp. 889-898, (1986)