锯齿环翅与平直环翅肋侧通道内涡流与传热特性的对比分析  

Comparative analysis of vortex motion and heat transfer characteristics in the channel of serrated and annular finned tube heat exchanger

作　　者：杨瑞霞 侯钧川 林志敏 宋智龙 王良璧 YANG Ruixia;HOU Junchuan;LIN Zhimin;SONG Zhilong;WANG Liangbi(Key Laboratory of Railway Vehicle Thermal Engineering of MOE,School of Mechanical Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学机电工程学院铁道车辆热工教育部重点实验室,甘肃兰州730070

出　　处：《热科学与技术》2024年第5期490-501,共12页Journal of Thermal Science and Technology

基　　金：国家自然科学基金资助项目(51676093);兰州交通大学百名青年优秀人才培养计划资助项目

摘　　要：圆管环翅肋侧通道中存在涡系间相互作用,翅片结构参数是影响其流动复杂的重要因素。以锯齿环翅与平直环翅为研究对象,基于SST k-ω湍流模型,通过改变翅片间距和翅片高度,对其流动通道内的涡流特性与传热强度进行数值模拟研究,并分析了涡流特性与传热强度之间的关系。结果表明:与平直环翅管相比,在Re=10 000~30 000时,锯齿翅片的时均努塞尔数提高约25%~38%,时均欧拉数提高约28%~41%;涡脱落频率增大约10%~20%,涡强度也更大,且振荡现象在锯齿翅片中不明显。对比两者的涡与传热的变化,均发现在翅片管后出现次级涡的位置换热较差,而在卡门涡脱落处换热效果较好,说明涡特性与传热强度之间具有对应关系。同时发现增大翅片间距涡的脱落加快,换热增强且阻力减小,增加翅片高度涡的脱落减缓,换热基本不变且阻力增大。There are vortex interactions in the channel formed by circular tube annular fins,and the geometrical parameters of the fin are the important factors affecting the flow complexity.Taking the serrated and annular fins as the research objects,based on the SSTk-ωturbulence model,the vortex motion characteristics and heat transfer intensity were numerically simulated in the flow channel with the changing fin spacings and fin heights,and the relationship between the vortex motion characteristics and heat transfer intensity was analyzed.The results show that,when Re=10000-30000,the time-averaged Nusselt number of serrated fins is increased by about 25%-38%,and the time-averaged Euler number is increased by about 28%-41%compared with the annular fins.The vortex shedding frequency is increased by about 10%-20%,the vortex intensity is also larger,and the oscillation phenomenon is less in the serrated fins.Comparing the changes of vortex and heat transfer,it is found that the heat transfer is poor at the position where the secondary vortex appears behind the finned tube,while the heat transfer is better where the Kármán vortex falls off.It is indicated the relationship between the vortex characteristics and the heat transfer intensity.Moreover,it is found that,with the increasing fin spacing,the vortex shedding frequency increases,the heat transfer is enhanced,and the resistance is reduced.With the increase of fin height,the vortex shedding frequency is slowed down,and the heat transfer is less changed and the resistance increases.

关 键 词：翅片管换热器 锯齿翅片 涡特性 传热特性 数值模拟 

分 类 号：TK124[动力工程及工程热物理—工程热物理]