壁面粗糙度效应对微流体流动特性的影响

中国机械工程 ›› 2015, Vol. 26 ›› Issue (9): 1210-1214.

壁面粗糙度效应对微流体流动特性的影响

谭德坤1,2;刘莹1

1.南昌大学,南昌,330031
2.南昌工程学院,南昌,330099

出版日期:2015-05-10 发布日期:2015-05-08
基金资助:
国家自然科学基金资助项目(51165031，50730007,11302095)

Effects of Wall Roughness on Pressure-driven Liquid Flow in Microchannels

Tan Dekun1,2;Liu Ying1

1.Nanchang University,Nanchang,330031
2.Nanchang Institute of Technology,Nanchang,330099

Online:2015-05-10 Published:2015-05-08
Supported by:
National Natural Science Foundation of China（No. 51165031，50730007,11302095）

摘要/Abstract

摘要：

壁面粗糙度对微流道流动特性有重要影响。分别用矩形、三角形和圆顶形粗糙元对壁面粗糙度进行模拟,详细讨论了雷诺数、粗糙元高度、粗糙元间距等因素对流速、压降及流动阻力的影响。结果表明:与光滑流道相比，粗糙度使壁面附近的流动发生明显改变，从而导致微流道内流速、压降及流阻高于经典理论预测值;微流道内流动阻力随着雷诺数及粗糙元高度的增大而增大，而随着粗糙元间距的增大,流动阻力逐渐减小。三种粗糙元相比，矩形粗糙元的影响最大,圆顶形次之,而三角形粗糙元的影响最小,可见在实际应用场合，确立合适的粗糙元形状对分析结果非常重要。

关键词: 壁面粗糙度, 微流道, 粗糙元, 泊肃叶数, 压降

Abstract:

Surface roughness may have significant impacts on microchannel flow performances. The rough surfaces were modeled herein by rectangular, dome-shamed and triangular roughness elements, respectively. The influences of Reynolds number, roughness height and roughness element spacing on velocity distributions, pressure drop and flow resistance were discussed in detail. Results show that the liquid flow near the channel wall is obviously changed by surface roughness, thereby causes flow velociy, pressure drop and Poiseuille number are larger than the classical value. The Poiseuille number increases with the increase of roughness height and Reynolds number, while decreases gradually when roughness element spacing increases. The roughness geometry also places significant effects on the flow characteristics, in three types of roughness elements, the impact of rectangular roughness elements on microchannel flow is the greatest, then the dome-shaped roughness elements, however,the influence of the triangular roughness elements is the weakest. This means that it is very important to choose an appropriate shape of roughness element for modeling the roughness microchannel in practical applications.

Key words: surface roughness;microchannel;roughness element;Poiseuille number;pressure , drop

中图分类号:

O351
TH117

谭德坤, 刘莹. 壁面粗糙度效应对微流体流动特性的影响[J]. 中国机械工程, 2015, 26(9): 1210-1214.

Tan Dekun, Liu Ying. Effects of Wall Roughness on Pressure-driven Liquid Flow in Microchannels[J]. China Mechanical Engineering, 2015, 26(9): 1210-1214.

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