On the microscopic foundation of dissipative particle dynamicsA. 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
received 26 February 2009; accepted in final form 21 April 2009; published May 2009
published online 27 May 2009
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.
47.11.-j - Computational methods in fluid dynamics.
47.11.St - Multi-scale methods.
47.57.-s - Complex fluids and colloidal systems.
© EPLA 2009