Mesoscopic two-phase model for describing apparent slip in micro-channel flowsR. Benzi1, L. Biferale1, M. Sbragaglia1, S. Succi2 and F. Toschi2, 3
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 in final form 22 March 2006
published online 12 April 2006
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.
47.55.D- - Drops and bubbles.
83.50.Rp - Wall slip and apparent slip.
47.11.-j - Computational methods in fluid dynamics.
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