0
TECHNICAL PAPERS

Influence of Ribbon Structure Rough Wall on the Microscale Poiseuille Flow

[+] Author and Article Information
Haoli Wang

Department of Fluid Engineering, School of Energy & Power Engineering, Xi’an Jiaotong University, 28 Xianning Western Road, Xi’an, Shaanxi, 710049, People’s Republic of Chinawanghaoli@mailst.xjtu.edu.cn

Yuan Wang

Department of Fluid Engineering, School of Energy & Power Engineering, Xi’an Jiaotong University, 28 Xianning Western Road, Xi’an, Shaanxi, 710049, People’s Republic of Chinawangyuan@mail.xjtu.edu.cn

Jiazhong Zhang

Department of Fluid Engineering, School of Energy & Power Engineering, Xi’an Jiaotong University, 28 Xianning Western Road, Xi’an, Shaanxi, 710049, People’s Republic of China

J. Fluids Eng 127(6), 1140-1145 (Jun 25, 2005) (6 pages) doi:10.1115/1.2060733 History: Received January 11, 2005; Revised June 25, 2005

The regular perturbation method is introduced to investigate the influence of two-dimensional roughness on laminar flow in microchannels between two parallel plates. By superimposing a series of harmonic functions with identical dimensional amplitude as well as the same fundamental wave number, the wall roughness functions are obtained and the relative roughness can be determined as the maximal value of the product between the normalized roughness functions and a small parameter. Through modifying the fundamental wave number, the dimensionless roughness spacing is changed. Under this roughness model, the equations with respect to the disturbance stream function are obtained and analyzed numerically. The numerical results show that flowing in microchannels are more complex than that in macrochannels; there exist apparent fluctuations with streamlines and clear vortex structures in microchannels; the flow resistances are about 5–80% higher than the theoretical value under different wall-roughness parameters. Furthermore, analysis shows that the effect of roughness on the flow pattern is distinct from that on the friction factor.

FIGURES IN THIS ARTICLE
<>
Copyright © 2005 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Model of microchannel and the coordinate system

Grahic Jump Location
Figure 2

Wall roughness functions with different fundamental wave numbers: (a) curves of h(x) and (b) curves of ks(x)

Grahic Jump Location
Figure 3

Variation of first-order dimensionless stream function (a) and velocity of the y direction (b) in a flow field at the position of rough elements under different relative roughness when α0=2π

Grahic Jump Location
Figure 4

Variation of first-order dimensionless stream function (a) and velocity in the y direction (b) in a flow field at the position of rough elements under different spacing when α0=2π and ε=0.05

Grahic Jump Location
Figure 5

First-order dimensionless stream function (a) and velocity in the y direction (b) influenced by the Reynolds number

Grahic Jump Location
Figure 6

Distributions of stream function and near-wall vortex structures at Re=100: (i) ε=0.02, s∕a=2; (ii) ε=0.02, s∕a=1; (iii) ε=0.05, s∕a=2; and (iv) ε=0.05, s∕a=1

Grahic Jump Location
Figure 7

Velocity fields under different wall parameters in full region (a) and in the near-wall region (b)

Grahic Jump Location
Figure 8

Friction factors influenced by the relative roughness

Grahic Jump Location
Figure 9

Friction factors influenced by the dimensionless roughness spacing

Grahic Jump Location
Figure 10

Friction factors influenced by Reynolds number

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In