Dissipative Particle Dynamics with Energy Conservation: Dynamic and Transport Properties

TL;DR

This paper investigates the thermal conductivity of the DPDE model with energy conservation through simulations and theoretical analysis, revealing how transport properties depend on parameters like thermal conductivity and particle interactions.

Contribution

It provides a theoretical framework for understanding transport coefficients in DPDE, including a local equilibrium approximation and scaling analysis for energy transport.

Findings

Theoretical predictions of thermal conductivity match simulations for large particle interactions.

Transport behavior varies with thermal conductivity parameter λ, showing diffusive dominance at small λ.

Different kinetic contributions to heat transport are identified depending on λ.

Abstract

Simulation results of the thermal conductivity ${\cal L}$ of Dissipative Particle Dynamics model with Energy Conservation (DPDE) are reported. We also present an analysis of the transport equations and the transport coefficients for DPDE based on a local equilibrium approximation. This approach is valid when the particle-particle thermal conductivity $\lambda$ and the friction coefficient $\zeta$ are large. A qualitative derivation of the scaling form of the kinetic contribution of the transport of energy is derived, yielding two different forms for the kinetic contribution to the heat transport, depending on the value of $\lambda$. We find agreement between the theoretically predicted value for ${\cal L}$ and the simulation results, for large $\lambda$ and many particles interacting at one time. Significant differences are found for small number of interacting particles, even with large $\lambda$. For smaller values of $\lambda$, the obtained macroscopic thermal conductivity is dominated by diffusive transport, in agreement with the proposed scaling form.