Size consistency in Smoothed Dissipative Particle Dynamics

TL;DR

This paper investigates how the size of mesoparticles affects thermodynamic consistency in SDPD simulations, introduces an energy-based reformulation, and proposes a numerical scheme that conserves key invariants.

Contribution

It provides a detailed analysis of size effects in SDPD, reformulates the equations in energy variables, and develops a conservation-preserving numerical scheme.

Findings

Thermodynamic properties depend on mesoparticle size.

Energy reformulation aligns SDPD with energy-conserving DPD.

Numerical scheme ensures invariants are conserved during simulations.

Abstract

Smoothed Dissipative Particle Dynamics (SDPD) is a mesoscopic method which allows to select the level of resolution at which a fluid is simulated. In this work, we study the consistency of the resulting thermodynamic properties as a function of the size of the mesoparticles, both at equilibrium and out of equilibrium. We also propose a reformulation of the SDPD equations in terms of energy variables. This increases the similarities with Dissipative Particle Dynamics with Energy conservation and opens the way for a coupling between the two methods. Finally, we present a numerical scheme for SDPD that ensures the conservation of the invariants of the dynamics. Numerical simulations illustrate this approach.