Dissipative Particle Dynamics: Effects of Parameterization and Thermostating Schemes on Rheology

Abstract

We report a sensitivity analysis for dissipative particle dynamics (DPD) method, showing that it is highly sensitive to parameterization, integration method, and thermostating schemes. Practical guidelines are presented to maintain Newtonian characteristics of DPD fluid at a possible range of shear rates over wide-ranging DPD parameters. The effects of cutoff radii and the weight functions exponent in DPD triple forces are studied on viscosity, and optimized ranges are recommended for effective temperature control. Moreover, the advantages and shortcomings of DPD method is manifested using alternative thermostats (Peters, Lowe-Andersen, and Nosé-Hoover-Lowe-Andersen) in simultaneously meeting proper temperature control and Newtonian behavior in moderate to high shear rate regimes. It was shown that improper temperature control may lead to nonphysical shear-thickening. Diverse ranges of simulation settings are identified that are capable of delivering Newtonian viscosities from 0.83 to 46.3 in DPD units. This study also aims to reduce the risk of numerical artefacts giving seemingly accurate results in single-species, suspensions, or other complex systems.