|
Subgrid-Scale Modeling for Large-Eddy Simulation
of Flows with Strongly Coupled Subgrid Physics
Carlos Pantano-Rubino
Sandia National Laboratories
Hosted by Andrew Siegel
10:30 AM, July 25, 2006
Building 221, Room A216
|
| |
This talk will present a (partial) view of the current state of affairs
in
subgrid scale modeling for large-eddy simulation (LES) of turbulent flows.
We will mostly discuss modeling of flows in which there is a strong coupling between turbulence and subresolution physical phenomena prevalent in wall-bounded, reactive, compressible and even
mixing flows under unequal transport properties; Prandtl and Schmidt
numbers very different from unity. The role and limitations of the widely
used Smagorinsky model for this kind of flows is the primary driving force
of new subgrid models. Some new avenues of research based on statistical
ensembles of analytical solutions of Navier-Stokes, like vortices, and the
more mathematical approximate deconvolution techniques will be presented.
It is recognized that subgrid modeling and numerical methods for LES play
a
role in the results. On the one hand, one should not develop numerical methods
that are too closely tied to the subgrid model , but
on the other hand, there are a number of properties that discretizations
should possess for LES. This includes numerical dissipation, stability,
aliasing errors, resolution adaptivity, and temporal integration issues
like stiffness. We will complement this presentation with examples
of flows
that can be successfully and accurately modeled using LES and examples of
flows that are not so well predicted using LES today. The computational
infrastructure required for these tasks will be discussed also to some
extent.
|
