Variation of molecular mean free path in confined geometries

Xie, Jianfei and Gibelli, Livio and Borg, Matthew K. and Henrich, Oliver and Lockerby, Duncan A. and Reese, Jason M. (2019) Variation of molecular mean free path in confined geometries. AIP Conference Proceedings, 2132. 090009. ISSN 1551-7616

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    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.

    ORCID iDs

    Xie, Jianfei, Gibelli, Livio, Borg, Matthew K., Henrich, Oliver ORCID logoORCID: https://orcid.org/0000-0003-0384-982X, Lockerby, Duncan A. and Reese, Jason M. ORCID logoORCID: https://orcid.org/0000-0001-5188-1627;