Hostname: page-component-7c8c6479df-p566r Total loading time: 0 Render date: 2024-03-29T14:35:56.362Z Has data issue: false hasContentIssue false

Simulation of gas flow in microchannels with a sudden expansion or contraction

Published online by Cambridge University Press:  10 May 2005

AMIT AGRAWAL
Affiliation:
Discipline of Mechanical Engineering, University of Newcastle, NSW 2308, Australia Present address: Department of Mechanical Engineering, Indian Institute of Technology, Mumbai 400076, India.
LYAZID DJENIDI
Affiliation:
Discipline of Mechanical Engineering, University of Newcastle, NSW 2308, Australia
R. A. ANTONIA
Affiliation:
Discipline of Mechanical Engineering, University of Newcastle, NSW 2308, Australia

Abstract

Two-dimensional simulations based on the isothermal lattice-Boltzmann method have been undertaken on microchannels with a sudden expansion or contraction. The study provides insight into the analysis of flows in complicated microdevices. The flow is pressure driven, and computations are performed for several Knudsen numbers, and area and pressure ratios, allowing the effects of compressibility and rarefaction to be assessed. The pressure drop for both the converging and diverging channels shows a discontinuity in slope at the junction, and is accompanied by a jump in velocity. The pressure drop in each section can be predicted well by the theory for straight channels. The mass flow ratio between converging and diverging channels is close to unity, and the streamlines are attached in both cases. It is deduced that compressibility and rarefaction have opposite effects on the flow. These results suggest that complex channels of the type considered here can be understood in terms of their primary units, and they experience only small secondary losses.

Type
Papers
Copyright
© 2005 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)