摘要
用数值方法分析了涡产生器高度对带分流器的曲面矩形涡产生器式翅片传热与流动的影响,为使用这类换热器的设计提供了理论依据.研究表明,在翅片间距为2.4 mm涡产生器高度为1.4 mm,1.7 mm,2.0 mm和2.3 mm时,在同一雷诺数Re下,涡发生器高度1.7 mm时产生的二次流强度最大.随着雷诺数Re的增大,努塞尔数Nu也不断增大,阻力系数f减小.在同一雷诺数下,不同曲面矩形涡发生器高度时努塞尔数Nu相差不明显,阻力系数随着曲面矩形涡发生器高度的增大而增大.二次流强度Se与努塞尔数Nu存在唯一对应的关系,二次流强度Se越大,努塞尔数Nu也越大,传热效果更好.以强化因子为衡量标准优选,曲面矩形涡发生器高度1.7 mm获得最佳的综合性能.
In this paper,the effect of the height of the vortex generator on heat transfer characteristics,friction characteristics and secondary flow intensity of a tube bank fin heat exchanger with curved rectangular vortex generators and flow distributors(CRVG fin with FRs)on the fins is studied numerically which can provide a basis for designing of heat exchanger using such fins.The results show that when the considered height is 1.4 mm,1.7 mm,2.0 mm and 2.3 mm respectively,the secondary flow intensity produced by the vortex generator at the height of 1.7 mm is the largest under the same Reynolds number.With the increase of Reynolds number,Nussel number increases,friction coefficient decreases.At the same Reynolds number,the Nussel numbers do not differ significantly at different vortex generator height,and the friction coefficient increases with the increase of the height of the curved rectangular vortex generator.There is a unique relationship between the secondary flow intensity and Nussel number,which shows that the larger the secondary flow intensity Se is,the larger Nussel number Nu is,and the better the heat transfer effect is.When the enhancement factor is selected as the standard,it is concluded that the best comprehensive performance of such fin is obtained when the height of the vortex generators is 1.7 mm.
作者
党伟
王良璧
DANG Wei;WANG Liang-bi(School of Mechanical Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Key Laboratoryof thermal engineering of Ministry of Education,Lanzhou Jiaotong University,Lanzhou 730070,China)
出处
《兰州交通大学学报》
CAS
2020年第2期85-93,共9页
Journal of Lanzhou Jiaotong University
基金
国家自然科学基金(51776093)
甘肃省高等学校科技成果转化项目(2018D-12)。
关键词
涡发生器高度
二次流
管翅式换热器
传热强化
数值模拟
height of vortex generators
secondary flow
circular tube bank fin heat exchanger
heat transfer enhancement
numerical simulation
