Variation of molecular mean free path in confined geometries

Jianfei Xie; Livio Gibelli; Matthew K. Borg; Oliver Henrich; Duncan A. Lockerby; Jason M. Reese

doi:10.1063/1.5119594

Variation of molecular mean free path in confined geometries

Jianfei Xie^*
, Livio Gibelli
, Matthew K. Borg
, Oliver Henrich
, Duncan A. Lockerby
, Jason M. Reese

^*Corresponding author for this work

Physics

Research output: Contribution to journal › Conference article › peer-review

1 Citation (Scopus)

145 Downloads (Pure)

Abstract

This paper aims to settle disputes in the literature about the spatial variation of the molecular mean free path (MFP) in confined geometries. The MFP of a gas is determined by using both molecular dynamics (MD) and the direct simulation Monte Carlo (DSMC) technique. In spatially-homogeneous cases, the numerical results exactly recover the kinetic theory predictions of a constant MFP. However, in microchannels, the MFP is found to vary near to the bounding walls and reduce at the surfaces to half of its bulk value as long as collisions between gas molecules and wall atoms are taken into account in the calculation of the MFP.

Original language	English
Article number	090009
Number of pages	7
Journal	AIP Conference Proceedings
Volume	2132
DOIs	https://doi.org/10.1063/1.5119594
Publication status	Published - 5 Aug 2019
Event	31st International Symposium on Rarefied Gas Dynamics, RGD 2018 - Glasgow, United Kingdom Duration: 23 Jul 2018 → 27 Jul 2018

Funding

The authors acknowledge the support of the UK’s Engineering and Physical Sciences Research Council (EPSRC) via grant nos. EP/N016602/1 and EP/R007438/1. JMR acknowledges the support of the Royal Academy of Engineering under the Chair in Emerging Technologies scheme. JFX thanks the National Natural Science Foundation of China (grant no. 51506110) for their support. OH acknowledges support from the EPSRC Early Career Research Software Engineer Fellowship Scheme (EP/N019180/2). The authors thank Dr Srinivasa Ramisetti for useful discussions.

Keywords

DSMC method
molecular mean free path (MFP)
molecular dynamics

Access to Document

10.1063/1.5119594

Xie-etal-2019-Variation-of-molecular-mean-free-path-in-confined-geometricsAccepted author manuscript, 1.07 MB

EPSRC Research Software Engineer Fellowship
Henrich, O. (Fellow)
EPSRC (Engineering and Physical Sciences Research Council)
1/07/17 → 31/07/21
Project: Research Fellowship

Cite this

@article{821d2b8dcc96408da46e70a0248389eb,

title = "Variation of molecular mean free path in confined geometries",

abstract = "This paper aims to settle disputes in the literature about the spatial variation of the molecular mean free path (MFP) in confined geometries. The MFP of a gas is determined by using both molecular dynamics (MD) and the direct simulation Monte Carlo (DSMC) technique. In spatially-homogeneous cases, the numerical results exactly recover the kinetic theory predictions of a constant MFP. However, in microchannels, the MFP is found to vary near to the bounding walls and reduce at the surfaces to half of its bulk value as long as collisions between gas molecules and wall atoms are taken into account in the calculation of the MFP.",

keywords = "DSMC method, molecular mean free path (MFP), molecular dynamics",

author = "Jianfei Xie and Livio Gibelli and Borg, \{Matthew K.\} and Oliver Henrich and Lockerby, \{Duncan A.\} and Reese, \{Jason M.\}",

year = "2019",

month = aug,

day = "5",

doi = "10.1063/1.5119594",

language = "English",

volume = "2132",

note = "31st International Symposium on Rarefied Gas Dynamics, RGD 2018 ; Conference date: 23-07-2018 Through 27-07-2018",

}

TY - JOUR

T1 - Variation of molecular mean free path in confined geometries

AU - Xie, Jianfei

AU - Gibelli, Livio

AU - Borg, Matthew K.

AU - Henrich, Oliver

AU - Lockerby, Duncan A.

AU - Reese, Jason M.

PY - 2019/8/5

Y1 - 2019/8/5

N2 - This paper aims to settle disputes in the literature about the spatial variation of the molecular mean free path (MFP) in confined geometries. The MFP of a gas is determined by using both molecular dynamics (MD) and the direct simulation Monte Carlo (DSMC) technique. In spatially-homogeneous cases, the numerical results exactly recover the kinetic theory predictions of a constant MFP. However, in microchannels, the MFP is found to vary near to the bounding walls and reduce at the surfaces to half of its bulk value as long as collisions between gas molecules and wall atoms are taken into account in the calculation of the MFP.

AB - This paper aims to settle disputes in the literature about the spatial variation of the molecular mean free path (MFP) in confined geometries. The MFP of a gas is determined by using both molecular dynamics (MD) and the direct simulation Monte Carlo (DSMC) technique. In spatially-homogeneous cases, the numerical results exactly recover the kinetic theory predictions of a constant MFP. However, in microchannels, the MFP is found to vary near to the bounding walls and reduce at the surfaces to half of its bulk value as long as collisions between gas molecules and wall atoms are taken into account in the calculation of the MFP.

KW - DSMC method

KW - molecular mean free path (MFP)

KW - molecular dynamics

U2 - 10.1063/1.5119594

DO - 10.1063/1.5119594

M3 - Conference article

AN - SCOPUS:85070693082

SN - 0094-243X

VL - 2132

JO - AIP Conference Proceedings

JF - AIP Conference Proceedings

M1 - 090009

T2 - 31st International Symposium on Rarefied Gas Dynamics, RGD 2018

Y2 - 23 July 2018 through 27 July 2018

ER -

Variation of molecular mean free path in confined geometries

Abstract

Funding

Keywords

Access to Document

Fingerprint

Projects

EPSRC Research Software Engineer Fellowship

Cite this