摘要
球窝作为一种小流阻的强化传热结构，在微型换热器中有较大的发展前景．该文采用实验与数值相结合的方法，研究层流条件下布置球窝结构的矩形通道内部的流动与换热特性，比较了不同球窝深度、不同Reynolds（雷诺）数对其强化换热特性的影响，并与光滑结构进行了对比．研究结果表明：随着Reynolds数的增加，换热效果逐渐增强．在3种Reynolds数（Re=500，1000，1500）工况下，在球窝深度直径比在0．1～0．2之间时，球窝内部均存在流动分离且分离点位于球窝中心之前，球窝换热特性最好，与实验得出深度直径比为0．2时换热效果最好相吻合．在同一Reynolds数条件下，随着球窝深度的增加，其阻力特性逐渐降低．综合热特性随着Reynolds数的增大呈现下降趋势．
The dimple has bright prospect in the micro heat exchanger for smaller flow resist- ance and better heat transfer enhancement characteristics. Numerical and experimental study of heat transfer enhancement based on the structure of cooling rectangular channels with dimples was carried out. The flow structure and heat transfer characteristics in laminar air flow with dif- ferent dimple depths and different Reynolds numbers were investigated, and the results were compared with those of the corresponding fiat cases. The results show that： with the increasing Reynolds number, the heat transfer effect gradually increases; there exists the best dimple depth between 1 nun and 2 mm at the 3 Reynolds numbers （Re = 500, 1 000, 1 500） ; the flow separation occurs inside the dimple and the separation point is located in front of the dimple center, which results in the best heat transfer characteristics; at the same Reynolds number, the resistance characteristics decrease with the increasing dimple depth, and the thermal per- formance decreases with the increasing Reynolds number.
出处
《应用数学和力学》
CSCD
北大核心
2014年第3期254-263,共10页
Applied Mathematics and Mechanics
关键词
球窝
换热
数值模拟
实验
dimple
heat transfer
numerical simulation
experiment
