Multi-relaxation Model Research Articles

Моделирование диэлектрической релаксации в глинах при отрицательных и положительных температурах

Experimental data on measuring the complex dielectric constant (CDP) of clays with full moistening with distilled water in the frequency range from 1 kHz to 8.5 GHz at temperatures from -15 to +25 °C are presented. The modeling of the dependences of is carried out by a multirelaxation model that takes into account the relaxation of free and bound water, as well as relaxation at the bound water - mineral and bound water - air boundaries. It is shown that at temperatures below -5 °C, a relaxation process appears in the CDP spectrum due to polarization at the bound water - ice or ice - mineral interface. The relationship between the parameters of this relaxation process and the petrophysical characteristics of the rock is found.

QUASIEQUILIBRIUM LATTICE BOLTZMANN MODELS WITH TUNABLE PRANDTL NUMBER FOR INCOMPRESSIBLE HYDRODYNAMICS

Recently, it was shown that energy conserving (EC) lattice Boltzmann (LB) model is more accurate than athermal LB model for high-resolution simulations of athermal flows. However, in the sub-grid (SG) domain, the behavior is found to be opposite. In this work, we show that via multi-relaxation model, it is possible to preserve the accuracy of the EC LB for both SG and direct numerical simulation (DNS) models. We show that by introducing a nonunit Prandtl number, under-resolved simulations can also be performed quite efficiently, a property which we attribute to the enhanced sound-relaxation.