Document 
Eur. Phys. J. E 26, 115-122 (2008)
DOI: 10.1140/epje/i2007-10311-4
Tunable-slip boundaries for coarse-grained simulations of fluid flow
J. Smiatek1, M. P. Allen2 and F. Schmid11 Physics Faculty, Universität Bielefeld, D-33615, Bielefeld, Germany
2 Department of Physics and Centre for Scientific Computing, University of Warwick, CV4 7A1, Coventry, UK
schmid@physik.uni-bielefeld.de
Received 31 October 2007 / Published online 21 April 2008
Abstract
On the micro- and nanoscale, classical hydrodynamic boundary conditions such as the no-slip condition no longer apply. Instead, the flow profiles exhibit "slip" at the surface, which is characterized by a finite slip length (partial slip). We present a new, systematic way of implementing partial-slip boundary conditions with arbitrary slip length in coarse-grained computer simulations. The main idea is to represent the complex microscopic interface structure by a spatially varying effective viscous force. An analytical equation for the resulting slip length can be derived for planar and for curved surfaces. The comparison with computer simulations of a DPD (dissipative particle dynamics) fluid shows that this expression is valid from full slip to no slip.
PACS47.11.-j - Computational methods in fluid dynamics.
47.61.-k - Micro- and nano- scale flow phenomena. Correspondence: schmid@physik.uni-bielefeld.de
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2008