摘要
以蒸馏水为实验工质,用紫铜管和PVC管组成间隙尺寸为0.540～2.685 mm的窄环形流道中,对雷诺数在200～6 000的5组窄环形通道内的流体阻力特性进行了实验研究。结果表明:与圆管相比,窄环形通道内流体流动出现了从层流向湍流过渡提前的现象,且流态的转捩雷诺数随着窄环隙尺寸的减小而减小。常规环形通道与窄环形通道的临界间隙尺寸约为2.5 mm,间隙小于2.5 mm的窄环形通道的摩擦阻力系数值随着环隙尺寸的增大而增大。
Fluid friction characteristics were experimented and studied on five group narrow annuli with the gap size ranging from 0.540 mm to 2.685 mm which are composed of copper tube and PVC pipe,and distilled water used as working fluid in the experiment.The Reynolds number range in the experiment is from 200 to 6 000.The experimental results show comparing with circular pipe,the narrow annuli advance the Reynolds number from the laminar to the rapids and friction factor goes down with decrease of the gap size.It was found that the critical gap size of the conventional annuli size and the narrow annuli approximately is 2.5 mm,friction factor increased with the increase of the gap size when the gap is smaller than 2.5 mm.
出处
《武汉理工大学学报》
CAS
CSCD
北大核心
2010年第19期85-88,共4页
Journal of Wuhan University of Technology
关键词
窄环隙
阻力系数
传热系数
雷诺数
micro-channels
friction coefficient
heat transfer coefficient
Reynolds number
