Nature of self-diffusion in two-dimensional fluids
Self-diffusion in a two-dimensional simple fluid is investigated by both analytical and numerical means. We investigate the anomalous aspects of self-diffusion in two-dimensional fluids with regards to the mean square displacement, the time-dependent diffusion coefficient, and the velocity autocorrelation function (VACF) using a consistency equation relating these quantities. Here, we numerically confirm the consistency equation by extensive molecular dynamics simulations for finite systems, corroborate earlier results indicating that the kinematic viscosity approaches a finite, non-vanishing value in the thermodynamic limit, and establish the finite size behavior of the diffusion coefficient. We obtain the exact solution of the consistency equation in the thermodynamic limit and use this solution to determine the large time asymptotics of the mean square displacement, the diffusion coefficient, and the VACF. An asymptotic decay law of the VACF resembles the previously known self-consistent form, 1/($$t\sqrt{In t)}$$ however with a rescaled time.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR); Korea Advanced Institute of Science and Technology (KAIST)
- Grant/Contract Number:
- SC0008271; AC02-05CH11231; A0702001005
- OSTI ID:
- 1437764
- Alternate ID(s):
- OSTI ID: 1432222
- Journal Information:
- New Journal of Physics, Journal Name: New Journal of Physics Vol. 19 Journal Issue: 12; ISSN 1367-2630
- Publisher:
- IOP PublishingCopyright Statement
- Country of Publication:
- United Kingdom
- Language:
- English
Web of Science
Similar Records
Modified Closures in Monte Carlo Algorithms for Diffusive Binary Stochastic Media Transport Problems
Flow regimes for fluid injection into a confined porous medium