To investigate the gas flow characteristics in tight porous media, a microscale lattice Boltzmann (LB) model with the regularization procedure is firstly adopted to simulate gas flow in three-dimensional (3D) digital rocks. A shale digital rock and a sandstone digital rock are reconstructed to study the effects of pressure, temperature and pore size on microscale gas flow. The simulation result...

In this paper, we propose a new semi-Lagrangian scheme for the polyatomic ellipsoidal BGK model. order to avoid time step restrictions coming from convection term and small Knudsen number, combine approach with an implicit treatment relaxation term. We show how explicitly solve step, thus obtaining efficient stable any number. also derive explicit error estimate on convergence of proposed every...

Since the proposal of differential cryptanalysis and linear cryptanalysis in 1991 and 1993, respectively, the resistance to these cryptanalysis has been studied. In FSE2, Knudsen proposed a method of attacking block ciphers that used the higher order differential, and in FSE4, Jakobsen and Knudsen applied it to a cipher proposed by Nyberg and Knudsen. Their approach, however, requires large com...

A new closure for Grad’s 13 moment equations is presented that adds terms of SuperBurnett order to the balances of pressure deviator and heat flux vector. The additional terms are derived from equations for higher moments by means of the distribution function for 13 moments. The resulting system of equations contains the Burnett and Super-Burnett equations when expanded in a series in the Knuds...

We use the discrete kinetic theory with the free-orientation parameter being fixed (π/4) to derive the macroscopic velocity field for many particles flowing through a microdomain. Our results resemble qualitatively other hydrodynamical solutions. The V-shaped velocity field changes as the dominant physical parameter (Knudsen number) varies. We also briefly discuss the possible mechanism due to ...