8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Tue 611:23-14:00P9.27Cell-level canonical sampling by velocity scaling formultiparticle collision dynamics simulationsChien-Cheng Huang 11 Forschungszentrum Juelich, Forschungszentrum Juelich, 52425, Juelich, GermanyFor simulations of complex fluids under non-equilibrium conditions, such as shear or capillaryflow, a local thermostat is often needed to keep the temperature constant. In order to reproduce thecorrect statistical properties, a thermostat is required that corresponds to a canonical ensemble.We propose a local Maxwellian thermostat for the multiparticle collision dynamics algorithm.The algorithm is based on a scaling of the relative velocities of the fluid particles within a collisioncell. The scaling factor is determined from the distribution of the kinetic energy within sucha cell. Thereby the algorithm ensures that the distribution of the relative velocities is givenby the Maxwell-Boltzmann distribution. We perform various non-equilibrium simulations forfluids in shear and pressure-driven flow, which confirm the validity of the proposed simulationscheme [1]. In addition, we determine the dynamic structure factors for fluids with and withoutthermostat, which exhibit significant differences due to suppression of the diffusive part of theenergy transport of the isothermal system.[1] C. -C. Hunag, A. Chatterji, G. Sutmann, G. Gompper, R. G. Winkler, J. Comput. Phys., 229, 168 (2010)27