Direct simulation at the pore-scale is crucial to unravel rarefaction effect on gas transport in tight porous media. To satisfy dual demands modeling accuracy and computation effort, an appropriate method must be chosen. This work, therefore, evaluates four numerical methods for rarefied flows a two-dimensional (2D) model media over wide range of rarefaction. These are incompressible Navier-Sto...

We study a liquid droplet moving inside rarefied gas. In other words, we consider two-phase flow with and gas phases an interface between the two which deforms respect to time space. The phase is modelled by Bhatanager–Gross–Krook (BGK) model of Boltzmann equation. incompressible Navier–Stokes equations. Interface boundary conditions for are presented. BGK solved semi-Lagrangian scheme meshfree...

The effect of gas rarefaction on the propagation two-dimensional vibroacoustic disturbances generated by a nonuniformly oscillating plane is studied. Closed-form descriptions are obtained in free-molecular (left panel figure) and continuum (right panel) limits complemented direct simulation Monte Carlo results. impacts signal decay rate directivity pattern highlighted rationalized.