Issue
EPL
Volume 86, Number 4, May 2009
Article Number 44001
Number of page(s) 6
Section Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics
DOI http://dx.doi.org/10.1209/0295-5075/86/44001
Published online 27 May 2009
EPL, 86 (2009) 44001
DOI: 10.1209/0295-5075/86/44001

On the microscopic foundation of dissipative particle dynamics

A. Eriksson1, 2, M. Nilsson Jacobi2, J. Nyström2 and K. Tunstrøm2

1   Department of Physics, University of Gothenburg - SE-41296 Göteborg, Sweden, EU
2   Complex Systems Group, Department of Energy and Environment, Chalmers University of Technology SE-41296 Göteborg, Sweden, EU

kolbjorn@chalmers.se

received 26 February 2009; accepted in final form 21 April 2009; published May 2009
published online 27 May 2009

Abstract
Mesoscopic-particle–based fluid models, such as dissipative particle dynamics, are usually assumed to be coarse-grained representations of an underlying microscopic fluid. A fundamental question is whether there exists a map from microscopic particles in these systems to the corresponding coarse-grained particles, such that the coarse-grained system has the same bulk and transport properties as the underlying system. In this letter, we investigate the coarse-graining of microscopic fluids using a Voronoi-type projection that has been suggested in several studies. The simulations show that the projection fails in defining coarse-grained particles that have a physically meaningful connection to the microscopic fluid. In particular, the Voronoi projection produces identical coarse-grained equilibrium properties when applied to systems with different microscopic interactions and different bulk properties.

PACS
47.11.-j - Computational methods in fluid dynamics.
47.11.St - Multi-scale methods.
47.57.-s - Complex fluids and colloidal systems.

© EPLA 2009