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arXiv · 1702.04102

A comment on `An improved macroscale model for gas slip flow in porous media'

Lei Wu·Minh Tuan Ho·Lefki Germanou·Xiao-Jun Gu·Chang Liu·Kun Xu·Yonghao Zhang
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Abstract

In a recent paper by Lasseux, Vald\'{e}s-Parada and Porter (J.~Fluid~Mech. \textbf{805} (2016) 118-146), it is found that the apparent gas permeability of the porous media is a nonlinear function of the Knudsen number. However, this result is highly questionable, because the adopted Navier-Stokes equations and the first-order velocity-slip boundary condition are first-order (in terms of the Knudsen number) approximations of the Boltzmann equation and the kinetic boundary condition for rarefied gas flows. Our numerical simulations based on the Bhatnagar-Gross-Krook kinetic equation and regularized 20-moment equations prove that the Navier-Stokes equations with the first-order velocity-slip boundary condition are only accurate at a very small Knudsen number limit, where the apparent gas permeability is a linear function of the Knudsen number.

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Lei Wu, Minh Tuan Ho, Lefki Germanou, Xiao-Jun Gu, Chang Liu, Kun Xu, Yonghao Zhang. 2017-02-14. A comment on `An improved macroscale model for gas slip flow in porous media'. https://arxiv.org/abs/1702.04102

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