International audienceThis work focuses on the slip phenomenon at the fluid-solid interface accompanying Poiseuille flow of simple binary miscible fluids in a slit nanopore. To explore such flows, molecular dynamics simulations are used on Lennard-Jones binary mixtures composed of species of varying affinities with the walls. The results have shown that the apparent slip magnitude at the fluid-solid interface depends largely on the species that is dominant in contact with the walls. In addition, it has been shown that the velocity profiles of each species (of different "wettability") does not superpose with the velocity profile of the mixture and such a result points out the limitations of the classical approaches based on a single momentum conservation equation to deal with mixtures flow in nanochannels

The Poiseuille-Rayleigh-Bénard problem, involving the onset of thermoconvective structures in channels heated from below, was the subject of many theoretical, numerical and knowledge, this problem was never studied for supercritical fluids. The objective of this paper is to study the influence of the specific properties of such fluids on thermoconvective instability phenomena compared with those observed in the perfect gas case. The effect of the distance to the critical point is also investigated. The numerical approach used is based on the Navier-Stokes equations in the framework of the low Mach number approximation.

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