Investigation of the Klinkenberg effect in a micro/nanoporous medium by direct simulation Monte Carlo method

Abstract

The pressure-driven gas transport characteristics through a porous medium consisting of arrays of discrete elements is investigated by using the direct simulation Monte Carlo (DSMC) method. Different porous structures are considered, accounting for both two-and three-dimensional arrangements of basic microscale and nanoscale elements. The pore scale flow patterns in the porous medium are obtained, and the Knudsen diffusion in the pores is studied in detail for slip and transition flow regimes. A new effective pore size of the porous medium is defined, which is a function of the porosity, the tortuosity, the contraction factor, and the intrinsic permeability of the porous medium. It is found that the Klinkenberg effect in different porous structures can be fully described by the Knudsen number characterized by the effective pore size. The accuracies of some widely used Klinkenberg correlations are evaluated by the present DSMC results. It is also found that the available correlations for apparent permeability, most of which are derived from simple pipe or channel flows, can still be applicative for more complex porous media flows, by using the effective pore size defined in this study.

Accurate permeability prediction in tight gas rocks via lattice Boltzmann simulations with an improved boundary condition

“…5b and a DSMC study in Ref. (Yang and Weigand 2018). The good agreement between the estimated / and the BKC correlation shows a strong applicability the MBB+SR BC to the gas flow through complex pore structures.…”

An Investigation of Transition Flow in Porous Media by Event Driven Molecular Dynamics Simulation

“…Davies (1952) proposed a permeability calculation for flow within the fibrous structure with the help of an empirical correlation, including porosity and fiber diameter. In the study of Yang and Weigand (2018), where the Klinkenberg effect is investigated, the pressure-driven gas flow characteristics through a porous medium was examined in the slip and transition regime with the help of the DSMC method.…”

A Stochastic Two-Scale Model for Rarefied Gas Flow in Highly Heterogeneous Porous Media

“…The relevance of constrictions was highlighted in Zheng et al (2016), studying the regular multi-scale Sierpinski carpet type of topology. Related to this, several studies have investigated the effect of rarefaction in topologies defined by simple regular patterns (Yang and Weigand 2018) and topologies with self-affine fractal nature (Zheng et al 2013;Wu and Chen 2016). It has also been shown that the effect of rarefaction, i.e.…”

“…Instead, it also depends on porosity (Meghdadi Isfahani 2017), heterogeneity (Zheng et al 2017;Germanou et al 2018) and anisotropy (Wang et al 2016;Germanou et al 2018), which doubtlessly complicates the analysis of rarefied gas in porous media. This underlines the importance of considering the structure of the pore topology, which significantly affects the behaviour of the flow (Yang and Weigand 2018), preventing a universal description to be developed (Kalarakis et al 2012).…”