Density-Dependent Finite System-Size Effects in Equilibrium Molecular Dynamics Estimation of Shear Viscosity: Hydrodynamic and Configurational Study
| Autor: | Eok Kyun Lee, John J. Kozak, Kang-Sahn Kim, Changho Kim, George Em Karniadakis |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Chemical Physics (physics.chem-ph)
Physics 010304 chemical physics Shear viscosity Autocorrelation Fluid Dynamics (physics.flu-dyn) Finite system FOS: Physical sciences General Physics and Astronomy Mechanics Physics - Fluid Dynamics Computational Physics (physics.comp-ph) 010402 general chemistry Kinetic energy 01 natural sciences 0104 chemical sciences Term (time) Physics::Fluid Dynamics Molecular dynamics Density dependent Physics - Chemical Physics 0103 physical sciences Physical and Theoretical Chemistry Scaling Physics - Computational Physics |
| Popis: | We study the intrinsic nature of the finite system-size effect in estimating shear viscosity of dilute and dense fluids within the framework of the Green-Kubo approach. From extensive molecular dynamics simulations, we observe that the size effect on shear viscosity is characterized by an oscillatory behavior with respect to system size $L$ at high density and by a scaling behavior with an $L^{-1}$ correction term at low density. Analysis of the potential contribution in the shear-stress autocorrelation function reveals that the former is configurational and is attributed to the inaccurate description of the long-range spatial correlations in finite systems. Observation of the long-time inverse-power decay in the kinetic contribution confirms its hydrodynamic nature. The $L^{-1}$ correction term of shear viscosity is explained by the sensitive change in the long-time tail obtained from a finite system. |
| Databáze: | OpenAIRE |
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