Compressibility Effect on Slip Flow in Non-Circular Microchannels

Abstract

Microscale fluid dynamics has received intensive interest due to the emergence of micro-electro-mechanical systems (MEMS) technology. When the mean free path of the gas is comparable to the channel's characteristic dimension, the continuum assumption is no longer valid and a velocity slip may occur at the duct walls. Non-circular cross sections are common channel shapes that can be produced by microfabrication. The non-circular microchannels have extensive practical applications in MEMS. Compressibility effect on slip flow in non-circular microchannels has been examined and simple models are proposed to predict the pressure distribution and mass flow rate for slip flow in most non-circular microchannels. The effects of momentum changes are also considered in the models. The accuracy of the developed models has been examined with some experimental measurements and numerical analysis. The model predictions and experimental data are in good agreement. The developed models may be used to predict mass flow rate and pressure distribution of slip flow in non-circular microchannels.

KEY WORDS:

• slip flow
• microchannels
• pressure distribution
• mass flow rate

The authors acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC).