Journal Article

FZJ-2015-01078

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Thermostat for nonequilibrium multiparticle-collision-dynamics simulations

Huang, C.-C. (Corresponding Author)FZJ* ; Varghese, A.FZJ* ; Gompper, G.FZJ* ; Winkler, R. G.FZJ*

2015
APS College Park, Md.

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Please use a persistent id in citations: http://hdl.handle.net/2128/8325  doi:10.1103/PhysRevE.91.013310

Abstract: Multiparticle collision dynamics (MPC), a particle-based mesoscale simulation technique for complex fluid, is widely employed in nonequilibrium simulations of soft matter systems. To maintain a defined thermodynamic state, thermalization of the fluid is often required for certain MPC variants. We investigate the influence of three thermostats on the nonequilibrium properties of a MPC fluid under shear or in Poiseuille flow. In all cases, the local velocities are scaled by a factor, which is either determined via a local simple scaling approach (LSS), a Monte Carlo-like procedure (MCS), or by the Maxwell-Boltzmann distribution of kinetic energy (MBS). We find that the various scaling schemes leave the flow profile unchanged and maintain the local temperature well. The fluid viscosities extracted from the various simulations are in close agreement. Moreover, the numerically determined viscosities are in remarkably good agreement with the respective theoretically predicted values. At equilibrium, the calculation of the dynamic structure factor reveals that the MBS method closely resembles an isothermal ensemble, whereas the MCS procedure exhibits signatures of an adiabatic system at larger collision-time steps. Since the velocity distribution of the LSS approach is non-Gaussian, we recommend to apply the MBS thermostat, which has been shown to produce the correct velocity distribution even under nonequilibrium conditions.

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Contributing Institute(s):

1. Theorie der Weichen Materie und Biophysik (IAS-2)
2. Theorie der Weichen Materie und Biophysik (ICS-2)

Research Program(s):

1. 551 - Functional Macromolecules and Complexes (POF3-551) (POF3-551)

Appears in the scientific report 2015

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Database coverage:
; ; ; Current Contents - Physical, Chemical and Earth Sciences ; IF < 5 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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