Dynamical regimes in DPD

TL;DR

This paper analyzes the velocity autocorrelation function in Dissipative Particle Dynamics, identifying two regimes based on friction levels, supported by theoretical analysis and numerical simulations.

Contribution

It introduces a theoretical framework distinguishing low and high friction regimes in DPD and validates it with numerical simulations.

Findings

Mean field behavior at low friction matches kinetic theory predictions.

High friction regime shows dominant collective hydrodynamic effects.

Numerical simulations confirm the theoretical predictions.

Abstract

We discuss theoretically the behavior of the velocity autocorrelation function in the Dissipative Particle Dynamics model. Two dynamical regimes are identified depending on the dimensionless model parameters. For low frictions a mean field behavior is observed in which the kinetic theory for DPD provides good predictions. For high frictions, collective hydrodynamic effects are dominant. We have performed numerical simulations that validate the theory presented.