WIT Press


The Influence Of Knudsen Number On The Hydrodynamic Development Length Within Parallel Plate Micro-channels

Price

Free (open access)

Paper DOI

10.2495/AFM020191

Volume

36

Pages

12

Published

2002

Size

497 kb

Author(s)

R.W. Barber & D.R. Emerson

Abstract

One of the major difficulties i n predicting the flow of gases through micron-sized channels can be attributed to the breakdown of the continuum flow assumption in the Navier-Stokes equations. If the dimensions of a channel are comparable to the mean free path of the gas molecules, the fluid can no longer be regarded as being in thermodynamic equilibrium and a variety of non-continuum or rarefaction effects will occur. Velocity profiles, mass flow rates and boundary wall shear stresses are all influenced by the non-continuum regime. In addition, the length of the hydrodynamic development region at the entrance to a channel may also be affected. The present study examines the role of the Reynolds and Knudsen numbers on the hydrodynamic development length at the entrance to parallel plate micro-channels. Numerical simulations are carried out over a range of Knudsen numbers covering the continuum and slip-flow regimes (0 Keywords