A mesoscopic approach for multi-phase flows in nano-corrugated channels

摘要

An approach based on a lattice version of the Boltzmann kinetic equation fordescribing multi-phase flows in nano- and micro-corrugated devices is proposed.We specialize it to describe the wetting/dewetting transition of fluids inpresence of nanoscopic grooves etched on the boundaries. This approach permitsto retain the essential supra-molecular details of fluid-solid interactionswithout surrendering -actually boosting- the computational efficiency ofcontinuum methods. The mesoscopic method is first validated quantitativelyagainst Molecular Dynamics (MD) results of Cottin-Bizonne et al. [Nature Mater.2, 237 (2003)] and then applied to more complex situations which are hardlyaccessible to MD simulations. The resulting analysis confirms that surfaceroughness and capillary effects may conspire to promote a counter-intuitive butsignificant reduction of the flow drag with substantial enhancement in the massflow rates and slip-lengths in the micrometric range for highly hydrophobicsurfaces.