Transport coefficients of dissipative particle dynamics with finite time step

TL;DR

This paper analytically derives the viscosity of dissipative particle dynamics with finite time steps, including the Lowe-Anderson thermostat, and compares it with numerical data, providing insights into diffusion behavior.

Contribution

It presents an analytical derivation of DPD viscosity with finite time steps and compares it with numerical results, enhancing understanding of DPD transport properties.

Findings

Analytical expressions for DPD viscosity with finite time steps.

Good agreement between theory and numerical data.

Scaling of local relative velocity improves diffusion rates.

Abstract

The viscosity and self-diffusion constant of a mesoscale hydrodynamic method, dissipative particle dynamics (DPD), are investigated. The viscosity of DPD with finite time step, including the Lowe-Anderson thermostat, is derived analytically for the ideal-gas equation of state and phenomenologically for systems with soft repulsive potentials. The results agree well with numerical data. The scaling of the local relative velocity in molecular dynamics simulations is shown to be useful to obtain faster diffusion than for the DPD thermostat.