Efficient Schmidt number scaling in dissipative particle dynamics

TL;DR

This paper investigates how to efficiently scale the Schmidt number in dissipative particle dynamics simulations, proposing an optimal parameter strategy that enhances computational speed while maintaining accuracy.

Contribution

It provides a detailed parameter search and theoretical analysis to identify the most efficient way to increase the Schmidt number in DPD simulations without sacrificing accuracy.

Findings

Optimal parameter choices can triple simulation speed.

A comprehensive parameter space search guides efficient scaling.

Theoretical and numerical methods validate the proposed strategy.

Abstract

Dissipative particle dynamics is a widely used mesoscale technique for the simulation of hydrodynamics (as well as immersed particles) utilizing coarse-grained molecular dynamics. While the method is capable of describing any fluid, the typical choice of the friction coefficient $\gamma$ and dissipative force cutoff $r_c$ yields an unacceptably low Schmidt number $Sc$ for the simulation of liquid water at standard temperature and pressure. There are a variety of ways to raise $Sc$, such as increasing $\gamma$ and $r_c$, but the relative cost of modifying each parameter (and the concomitant impact on numerical accuracy) has heretofore remained undetermined. We perform a detailed search over the parameter space, identifying the optimal strategy for the efficient and accuracy-preserving scaling of $Sc$, using both numerical simulations and theoretical predictions. The composite results recommend a parameter choice that leads to a speed improvement of a factor of three versus previously utilized strategies.