摘要
采用局部非热平衡模型,在方腔左侧壁面布置不连续等温边界条件,数值模拟了固体骨架发热多孔介质方腔内的稳态非达西自然对流传热,探讨了不同等温边界布置方案及方腔的高宽比M/L对方腔内自然对流传热的影响规律。计算结果表明:由于单向重力影响,多孔介质方腔内流函数结构呈现上下不对称特性,而固体相温度场分布呈现出上下对称分布规律;流体相局部Nu数的大小及分布规律与等温边界的位置相关,局部Nu数随着Y=0.5值的增大而增加,固体相局部Nu数则以Y=0.5处为中心呈现上下对称分布规律。存在一个最佳ξ值及高宽比值,使得多孔介质方腔内的整体向外传热量达到最大值,等温边界布置于方腔上侧更有利于强化方腔整体的自然对流传热。
The steady non-Darcian natural convection in a square cavity filled with a heat-generating porous medium was studied numerically by adopting the local thermal non-equilibrium model. The SIMPLER algorithm was adopted to solve the momentum and energy equations. All of the walls of the enclosure are adiabatic except for the left wall, which is partially set as the cooling boundary condition. The simulation results show that the streamlines present asymmetric features in the height direction because of the gravitational factor and the isotherms of solid phase are symmetrical. The local Nusselt numbers of fluid phase are different when the location of isothermal boundary changes and they are symmetrical about the center point of height wall for solid phase. There exists an optimal value of and aspect ratio to enhance the heat transfer in the square enclosure. The total heat transfer in the enclosure can be enhanced by higher location of isothermal boundary.
出处
《化学工程》
CAS
CSCD
北大核心
2014年第2期18-22,49,共6页
Chemical Engineering(China)
基金
国家自然科学基金资助项目(51266006)
高等学校博士学科点专项科研基金新教师联合资助(20136101120010)
第54批中国博士后基金面上一等资助项目(2013M540768)
陕西省教育厅自然科学专项研究计划项目(12JK0585)
关键词
非热平衡模型
不连续等温边界
自然对流
数值模拟
local thermal non-equilibrium model
partially active walls
natural convection
numerical simulation
