6533b7d9fe1ef96bd126c31e
RESEARCH PRODUCT
Computing bulk and shear viscosities from simulations of fluids with dissipative and stochastic interactions
Gerhard JungFriederike Schmidsubject
PhysicsCauchy stress tensorForce profileShear viscosityDissipative particle dynamicsGeneral Physics and AstronomyFOS: Physical sciences02 engineering and technologyMechanicsCondensed Matter - Soft Condensed Matter021001 nanoscience & nanotechnology01 natural sciencesMolecular dynamicsShear (geology)0103 physical sciencesDissipative systemPeriodic boundary conditionsSoft Condensed Matter (cond-mat.soft)Physical and Theoretical Chemistry010306 general physics0210 nano-technologydescription
Exact values for bulk and shear viscosity are important to characterize a fluid and they are a necessary input for a continuum description. Here we present two novel methods to compute bulk viscosities by non-equilibrium molecular dynamics (NEMD) simulations of steady-state systems with periodic boundary conditions -- one based on frequent particle displacements and one based on the application of external bulk forces with an inhomogeneous force profile. In equilibrium simulations, viscosities can be determined from the stress tensor fluctuations via Green-Kubo relations; however, the correct incorporation of random and dissipative forces is not obvious. We discuss different expressions proposed in the literature and test them at the example of a dissipative particle dynamics (DPD) fluid.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-05-10 |