Europhys. Lett, 47 (2), pp. 145-151 (1999)
An alternative approach to dissipative particle dynamics
C. P. Lowe
Computational Physics, Delft University of Technology
Lorentzweg 1, 2628 CJ Delft, The Netherlands
(received 25 November 1998; accepted in final form 3 May 1999)
PACS. 05.40-a - Fluctuation phenomena, random processes, noise, and Brownian motion.
PACS. 02.70Ns - Molecular dynamics and particle methods.
PACS. 66.20+d - Viscosity of liquids; diffusive momentum transport.
We describe a simulation method based on combining the ideas behind Andersen's thermostat and dissipative particle dynamics (DPD). The result is a Galilean invariant thermostat that conserves momentum and enhances viscosity. It therefore displays the same characteristics as DPD. Our method differs primarily in that it satisfies detailed balance by construction. If a simple scheme is used to solve the equations of motion the thermostat does not disturb the equilibrium properties of the system, regardless of the time step. We illustrate the properties of the model by describing the results of various tests on the analogous system to the dissipative ideal gas. We show that with an appropriate choice of parameters it is practical to make the viscosity orders of magnitude greater than the diffusion coefficient. This is a criterion that should be satisfied if one is interested in studying the dynamics of mesoscopic systems.
Copyright EDP Sciences