微通道内流体流动的阻力特性  

AN EXPERIMENTAL STUDY ON FLUID FLOW CHARACTERISTICS IN MICROCHANNELS

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

出　　处：《工程热物理学报》2010年第6期998-1000,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：本文重点研究了微通道内入口效应和粗糙度等因素对流动阻力特性的影响。实验结果表明：对于粗糙度3．5％，水力直径为345μm的微圆管，入口段长度比常规管道短，转捩雷诺数Rec位于2000－2300，其内入口效应并不影响微管内流体从层流到湍流转捩的拐点位置；内径为112．6μm和169．8μm，高宽比为0．59和0．63以及粗糙分别为1．29％和2．03％的矩形微通道内流动由层流向湍流的转捩发生在Re≈1600～2800之间。实验结果表明，微尺度是微管内流体转捩提前的必要条件，但不是充分条件，拐点提前是由多因素综合作用所造成的结果，其机理有待于进一步研究。This paper investigates fluid flow fictional characteristics in microchannles with the emphasis of entrance effect and relative roughness influences. The experimental results indicate that there is no earlier transition from laminar to turbulent flow, and the critical Reynolds numbers of microchannels with the relative roughness of 3.5% and the hydraulic diameter of 345 μm locate at the range of 2000-2300, which indicates that the entrance effect does not influence the transition from laminar to turbulent flow; the hydraulic diameters of rectangular copper microehannels with relative roughness of 1.29%, 2.03%, aspect ratio of 0.59, 0.63, and the hydraulic diameter of 112.6 and 169.8 μm are investigated. The experimental results indicate that the critical Reynolds number locate at 1600-1800. The experimental results indicate that micro scale effect is the necessary but not sufficient condition for the earlier transition from laminar to turbulent flow which is caused by multiple factors, and the mechanism of the micro scale fluid flow need to be further studied.

关 键 词：微管流动 矩形微管 长径比 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]