纵向涡强化通道内换热的数值研究及机理分析  

Numerical Investigation and Analysis of the Heat Transfer Enhancement in Channel by Longitudinal Vortex Based on the Field Synergy Principle

作　　者：武俊梅[1] 陶文铨[1] 

机构地区：[1]西安交通大学动力工程多相流国家重点实验室

出　　处：《西安交通大学学报》2006年第9期996-1000,共5页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(50476046);教育部博士点基金资助项目(RFDP20030698015)

摘　　要：用三维数值模拟方法研究了纵向涡发生器用于层流矩形通道的流动换热特征．研究了Re（为800-3000）、涡发生器的冲角（分别为15°、30°、45°、60°、90°）、纵向涡发生器的形状对通道平均Nu和平均阻力系数的影响，并利用场协同原理进行了分析．结果发现：纵向涡发生器产生的二次流使全场速度和温度梯度之间的平均夹角减小，换热得到强化；纵向涡能改善包括涡发生器附近区域以及下游广阔区域的场协同性，而横向涡只可以改善涡发生器附近区域的场协同性，所以纵向涡可以强化整体换热，而横向涡只可以强化局部换热；对于光通道，协同角随Re增大而增大，但对于有纵向涡发生器的通道，协同角随着Re增大而减小．同时，在面积相同的条件下三角形小翼优于矩形小翼．3-D numerical simulations were presented for laminar flow and heat transfer characteristics in a rectangular channel with vortex generators. The effects of Reynolds number （from 800 to 3 000）, the attack angle of vortex generator（from 15°to 90°）and the shape of vortex generator were examined. The numerical results were analyzed based on the field synergy principle. It is found that the inherent mechanism of heat transfer enhancement by longitudinal vortex can be explained by the field synergy principle, namely the second flow generated by vortex generators re suits in the reduction of the intersection angle between the velocity and fluid temperature gradient. The longitudinal vortex improves the field synergy of the large downstream region of I.VG as well as the region near LVG, however transverse vortex only improves the synergy of the region near LVG. So longitudinal vortex enhances the integral heat transfer of the flow filed while transverse vortex enhances the local heat transfer only. And the synergy angle decreases with increasing Reynolds number for the channel with LVG to differ from the result obtained from the plain channel, and the triangle winglet performs better than the rectangle one under the same surface area condition.

关 键 词：纵向涡 强化换热 场协同 

分 类 号：TK124[动力工程及工程热物理—工程热物理]