DSMC investigation of rarefied gas flow through diverging micro- and nanochannels

Ebrahimi, Amin; Roohi, E.

doi:10.1007/s10404-017-1855-1

DSMC investigation of rarefied gas flow through diverging micro- and nanochannels

Title

DSMC investigation of rarefied gas flow through diverging micro- and nanochannels

Author

Ebrahimi, Amin (TU Delft (OLD) MSE-5; Ferdowsi University of Mashhad)
Roohi, E. (Ferdowsi University of Mashhad)

Date

2017

Abstract

Direct simulation Monte Carlo (DSMC) method with simplified Bernoulli trials (SBT) collision scheme has been used to study the rarefied pressure-driven nitrogen flow through diverging micro- and nanochannels. The fluid behaviours flowing between two plates with different divergence angles ranging between 0° and 17° are described at different pressure ratios (1.5 ≤ Π ≤ 2.5) and Knudsen numbers (0.03 ≤ Kn ≤ 12.7). The primary flow field properties, including pressure, velocity, and temperature, are presented for divergent micro- and nanochannels and are compared with those of a micro- and nanochannel with a uniform cross section. The variations of the flow field properties in divergent micro- and nanochannels which are influenced by the area change, the channel pressure ratio, and the rarefication are discussed. The results show no flow separation in divergent micro- and nanochannels for all the range of simulation parameters studied in the present work. It has been found that a divergent channel can carry higher amounts of mass in comparison with an equivalent straight channel geometry. A correlation between the mass flow rate through micro- and nanochannels, the divergence angle, the pressure ratio, and the Knudsen number has been suggested. The present numerical findings prove the occurrence of Knudsen minimum phenomenon in micro- and nanochannels with non-uniform cross sections.

Subject

Divergent micro/nanochannel
DSMC
Knudsen minimum
Rarefied gas flow
Simplified Bernoulli trials

To reference this document use:

http://resolver.tudelft.nl/uuid:41ad5dd0-f901-4e52-ab2d-ca49bd135de3

DOI

https://doi.org/10.1007/s10404-017-1855-1

Embargo date

2018-02-02

ISSN

1613-4982

Source

Microfluidics and Nanofluidics, 21 (2)