edu.ucar.opensky::technotes:315 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T17:21:22.819416 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7zs2vwh Statistical Closure to Derive a Subgrid-scale Modeling for Large Eddy Simulations of Three-dimensional Turbulence 1983-01-01T00:00:00Z publication https://n2t.org/ark:/85065/d7zs2vwh https://doi.org/10.5065/D64M92HB Chollet, J. author UCAR/NCAR - Library publisher A subgrid-scale modeling for the velocity field of threedimensional turbulence has been derived from a two-point closure by Chollet and Lesieur (1981); this model has been used in both two-point closure computations and direct numerical simulations of large scales. The same method is extended to the passive scalar, deriving an eddy diffusivity from the transfer of scalar variance through a given wave number kc. Some specific terms of the transfers are used to determine the modifications that the eddy quantities undergo because of the closeness of kc to dissipative or large scales. The eddy quantities can be split into two different contributions--an eddy viscosity (or diffusivity) and a higher-order dissipativity, the latter term corresponding to interactions between wave numbers in the neighborhood of the given wave number kc. Drastic differences between the dynamics of three- and two-dimensional turbulence are pointed out. The eddy quantities are used to parameterize the small scales of velocity and scalar fields, first in computations using the same two-point closure, then in direct numerical simulation of large scales. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Turbulence Models theme U.S. National Aeronautics and Space Administration Global Change Master Directory GCMD 2021-09-17 revision 11.2 NASA Global Change Master Directory originator Valids List: Science and Services Keywords Copyright Author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. None eng geoscientificInformation