矩形微管内摩擦阻力特性的实验研究  

EXPERIMENTAL STUDY OF FRICTIONAL CHARACTERISTICS ON RECTANGULAR MICROTUBES

作　　者：王樱[1] 刁彦华[1] 赵耀华[1] 

机构地区：[1]北京工业大学建筑工程学院,北京100124

出　　处：《工程热物理学报》2009年第5期841-843,共3页Journal of Engineering Thermophysics

基　　金：北京工业大学111人才工程资助项目(No.05004999200701);北京工业大学青年科研基金(No.97004016200701)

摘　　要：以极性液体蒸馏水、无水乙醇及非极性液体R113作为实验工质,流过水力直径为231.91μm、250.88μm、297.14μm和210.89μm,相应高宽比分别为0.90、0.70、0.90和0.42的由晶体生长方法得到的矩形紫铜微管,其相对粗糙度分别为1.47%、1.59%、1.48%和1.45%,测量其进出口压降与流量,从而获得摩擦阻力系数f与雷诺数Re的关系。实验结果表明:微管内流体的极性对微管流动阻力特性没有影响;同时实验结果显示对于粗糙度小于2%的矩形紫铜微管,其内壁面粗糙度对其流动阻力特性影响较小。当Re小于1600时,所有微管内的流动阻力特性与经典层流预测值几乎一致;而对于高宽比较小的矩形紫铜微管,当Re超过1600～1700时,微管的f值明显偏离经典层流预测值。In this study, polar liquid distilled water, ethanol and nonpolar liquid R113 were used as testing fluid, and let them flow through rectangular micrtubes which were made of copper by crystal growth method with hydraulic diameters of 231.91 μm, 250.88 μm, 297.14 μm and 210.89μm and the aspect ratio of 0.90. 0.70. 0.90 and 0.42, the relative roughness of the microtubes were estimated to be 1.47%, 1.59%, 1.48% and 1.45%, respectively. The pressure drop between the inlet and the outlet of the microtube as well as mass flow rates were measured and friction factors were calculated for different Reynolds numbers. The experimental results indicate that the polarity of the testing fluid is found to be negligible to the frictional characteristics, and meanwhile it also demonstrates that the microtubes with the relative roughness below 2% does not influence the frictional characteristics in flow conditions. When the Reynolds number is under 1600, the experimental data for frictional factors of all the testing fluids flow agree well with the theoretical correlation presented, when the Reynolds number is over the range of 1600-1700, the frictional factors of the microtube with the smallest aspect ratio deviate from the theoretical correlations obviously.

关 键 词：矩形微管 微管内流动 相对粗糙度 阻力特性 

分 类 号：TK124[动力工程及工程热物理—工程热物理]