Physics – Condensed Matter – Statistical Mechanics
Scientific paper
2010-12-20
New J. Phys. 13, 055020 (2011)
Physics
Condensed Matter
Statistical Mechanics
7 figures, 1 table. To appear in New J. Phys., special issue on "Granular Segregation"
Scientific paper
10.1088/1367-2630/13/5/055020
Diffusion induced by a thermal gradient in a granular binary mixture is analyzed in the context of the (inelastic) Enskog equation. Although the Enskog equation neglects velocity correlations among particles which are about to collide, it retains spatial correlations arising from volume exclusion effects and thus it is expected to apply to moderate densities. In the steady state with gradients only along a given direction, a segregation criterion is obtained from the thermal diffusion factor $\Lambda$ measuring the amount of segregation parallel to the thermal gradient. As expected, the sign of the factor $\Lambda$ provides a criterion for the transition between the Brazil-nut effect (BNE) and the reverse Brazil-nut effect (RBNE) by varying the parameters of the mixture (masses, sizes, concentration, solid volume fraction, and coefficients of restitution). The form of the phase diagrams for the BNE/RBNE transition is illustrated in detail for several systems, with special emphasis on the significant role played by the inelasticity of collisions. In particular, an effect already found in dilute gases (segregation in a binary mixture of identical masses and sizes {\em but} different coefficients of restitution) is extended to dense systems. A comparison with recent computer simulation results shows a good qualitative agreement at the level of the thermal diffusion factor. The present analysis generalizes to arbitrary concentration previous theoretical results derived in the tracer limit case.
No associations
LandOfFree
Thermal diffusion segregation in granular binary mixtures described by the Enskog equation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Thermal diffusion segregation in granular binary mixtures described by the Enskog equation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermal diffusion segregation in granular binary mixtures described by the Enskog equation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-453082