[GTP] New Developments in Turbulence Modeling. I. Theory November 4, 2010

[Carolyn Mueller]

Just a reminder of tomorrow's Seminar.

Carolyn Mueller
NCAR IMAGe
1850 Table Mesa Drive 
Boulder, CO 80305 
www.image.ucar.edu 
Tel: 303 497-2491
Fax: 303-497-2483



Carolyn Mueller wrote:
> Stefan Heinz
>
>
>
> University of Wyoming, Department of Mathematics
>
>
>
> For the foreseeable future we have to calculate turbulent flows as 
> observed in reality on the basis of equations that involve a 
> turbulence model. The development of computational methods that have a 
> predictive power requires the use of equations for large eddy 
> simulation (LES). In such equations we need a subgrid-scale (SGS) 
> turbulence model that accounts for the interaction of large and small 
> scales. Existing SGS models face three kinds of problems. First, the 
> consistency of models is not always clear: a turbulence model 
> describes correlations of a stochastic process, but there are SGS 
> models for which an underlying stochastic process does not exist. 
> Second, most SGS models need adjustments to the flow considered: such 
> methods have a limited predictive power. Third, LES are often too 
> expensive for applications to wall-bounded flows at high Reynolds 
> numbers, which have to be computed in many applications. Theoretical 
> solutions to these problems will be described in this first part of 
> two talks by explaining the basics of stochastic turbulence modeling 
> and the extension of these methods to dynamic and unified turbulence 
> models. The existence of an underlying stochastic turbulence model 
> overcomes the consistency issue. The dynamic model formulation 
> overcomes the need for adjusting the model to the flow considered 
> (this formulation does also overcome the adjustment of existing 
> dynamic methods by clipping or averaging coefficients to ensure the 
> stability of solutions). The unified model formulation overcomes the 
> cost issue of existing LES methods by the consistent integration of 
> LES and ensemble averaged equations.
>
> November 4, 2010
> FL2 Main Auditorium
> Room 1022
> Lecture 3:30 pm
>