圆形微通的对流换热特性研究.pdfVIP

第38 卷 第3 期 电 子 科 技 大 学 学 报 Vol.38 No.3 2009年5月 Journal of University of Electronic Science and Technology of China May 2009 圆形微通的对流换热特性研究 刘焕玲，贾建援，殷 磊 (西安电子科技大学机电工程学院 西安 710071) 【摘要】针对圆形微通道内流体的强迫对流问题，利用分离变量法求解了考虑轴向热传导、速度滑移和温度跳跃、粘度 耗散和入口效应等因素的圆形微通道的控制方程，给出了流体温度场和努塞尔数的计算表达式。对圆形微通道换热特性进行 了数值仿真，结果表明，受尺寸效应的影响，管径越小，平均对流换热系数越大。微通道的换热能力比宏观经典通道强，表 明在相同面积上做多个微通道比一个宏观大通道的换热效果好。 关 键 词 轴向热传导; 强迫对流; 努塞尔数; 速度滑移; 温度跳跃; 热入口效应 中图分类号 TK124 文献标识码 A doi:10.3969/j.issn.1001-0548.2009.03.038 Heat Transfer in Circular Microchannel LIU Huan-ling, JIA Jian-yuan, and YIN Lei (School of Electromechanical Engineering Xidian University Xian 710071) Abstract Forced convection of the circular microchannel is analyzed. The governing equations of circular microchannel are solved by separation of variables, with the considerations of axis conduction, viscous dissipation, thermal entrance and velocity slip. Then the expressions of temperature field and Nusselt number at uniform wall temperature conditions are achieved. Simulation of heat transfer is conducted. It is shown that the average heat transfer coefficient of microchannel is larger than macrochannel when the radius decreases for the small size effect, which means that face the average heat transfer coefficient of several microchannels on the same surface area is lager than that of one macrochnnel. Key words axial conduction; forced convection; nusselt number; thermal entrance; temperature jump; velocity slip [1] 由于微通道结构具有极好的换热性能 ，近年 管道流体的对流换热问题。利用分离变量法求解得 来微换热机理逐渐成为研究热点。但是现有的文献 到了流体的努塞尔数计