Thermostat for non-equilibrium multiparticle collision dynamics simulations
arXiv:1501.05734 · doi:10.1103/PhysRevE.91.013310
Abstract
Multiparticle collision dynamics (MPC), a particle-based mesoscale simulation technique for com- plex fluid, is widely employed in non-equilibrium 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 non-equilibrium 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 scal- ing 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 adi- abatic 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 non-equilibrium conditions.
12 pages, 5 figures in Phys. Rev. E, 2015
References in corpus (17)
- Canonical sampling through velocity-rescaling
- Hydrodynamic interactions and Brownian forces in colloidal suspensions: Coarse-graining over time and length-scales
- Multi-Particle Collision Dynamics -- a Particle-Based Mesoscale Simulation Approach to the Hydrodynamics of Complex Fluids
- Simulation of Claylike Colloids
- Hydrodynamic and Brownian Fluctuations in Sedimenting Suspensions
- Self-Propelled Rods near Surfaces
- Particle-Based Mesoscale Hydrodynamic Techniques
- Transport coefficients of off-lattice mesoscale-hydrodynamics simulation techniques
- Relevance of angular momentum conservation in mesoscale hydrodynamics simulations
- Dynamic correlations in stochastic rotation dynamics
- Mesoscale simulations of polymer dynamics in microchannel flows
- Stress Tensors of Multiparticle Collision Dynamics Fluids
- Flow-Induced Helical Coiling of Semiflexible Polymers in Structured Microchannels
- Multi-particle collision dynamics modeling of viscoelastic fluids
- Flow Generation by Rotating Colloids in Planar Microchannels
- A Stability Diagram for Dense Suspensions of Model Colloidal Al2O3-Particles in Shear Flow
- Formation and growth of clusters in colloidal suspensions