Mesoscopic two-phase model for describing apparent slip in micro-channel flows

¹ Dipartimento Fisica & INFN, Università Tor Vergata - via della Ricerca Scientifica 1 00133, Roma, Italy
² CNR-IAC - Viale del Policlinico 137, 00161 Roma, Italy
³ INFN - via Saragat 1, 44100 Ferrara, Italy

Received: 16 January 2006
Accepted: 22 March 2006

Abstract

The phenomenon of apparent slip in micro-channel flows is analyzed by means of a two-phase mesoscopic lattice Boltzmann model including non-ideal fluid-fluid and fluid-wall interactions. The weakly inhomogeneous limit of this model is solved analytically. The present mesoscopic approach permits to access much larger scales than molecular dynamics, and comparable with those attained by continuum methods. However, at variance with the continuum approach, the existence of a gas layer near the wall does not need to be postulated a priori, but emerges naturally from the underlying non-ideal mesoscopic dynamics. It is therefore argued that a mesoscopic lattice Boltzmann approach with non-ideal fluid-fluid and fluid-wall interactions might achieve an optimal compromise between physical realism and computational efficiency for the study of channel micro-flows.