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Updated: Jun 18, 2026
11:03
An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Stochastic subgrid-scale modelling for non-equilibrium geophysical flows
Meelis J Zidikheri1, Jorgen S Frederiksen
1Centre for Australian Weather and Climate Research, Bureau of Meteorology, Melbourne, Australia. m.zidikheri@bom.gov.au
Summary
This study applies non-equilibrium statistical mechanics to turbulence for parameterizing subgrid-scale eddies in large-eddy simulations (LESs). The new method accurately models ocean currents, improving geophysical fluid dynamics simulations.
Area of Science:
- Geophysical Fluid Dynamics
- Turbulence Theory
- Statistical Mechanics
Background:
- Parameterizing subgrid-scale eddies is crucial for large-eddy simulations (LESs) in geophysical fluid dynamics.
- Turbulence in geophysical flows, like the Antarctic Circumpolar Current, presents complex challenges for accurate modeling.
Purpose of the Study:
- To develop and apply a direct stochastic modeling scheme for parameterizing subgrid-scale eddies.
- To improve the accuracy of large-eddy simulations (LESs) in geophysical fluid dynamics.
Main Methods:
- Utilized methods from non-equilibrium statistical mechanics of turbulence.
- Employed a direct stochastic modeling scheme based on statistical closure theories.
- Developed a generalized Langevin equation to represent subgrid-scale eddy effects.
Main Results:
- Subgrid dissipation, stochastic forcing, and mean subgrid forcing were derived from high-resolution direct numerical simulations (DNS).
- The developed parametrization scheme significantly improved the agreement between LES and DNS results.
- Accurate modeling of baroclinically unstable subgrid-scale eddies was achieved.
Conclusions:
- The direct stochastic modeling approach provides a robust method for parameterizing subgrid-scale eddies in LESs.
- This technique enhances the fidelity of geophysical fluid dynamics simulations, particularly for flows like the Antarctic Circumpolar Current.
- The study demonstrates the successful application of advanced statistical mechanics to practical problems in computational fluid dynamics.
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