CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Wiki > Linear eddy viscosity models

Linear eddy viscosity models

From CFD-Wiki

(Difference between revisions)
Jump to: navigation, search
Enda.bigarella (Talk | contribs)
(New page: These are turbulence models in which the Reynolds stresses are modelled by a ''linear constitutive relationship'' with the ''mean...)
Newer edit →

Revision as of 17:12, 30 October 2009

These are turbulence models in which the Reynolds stresses are modelled by a linear constitutive relationship with the mean flow straining field, such as:

 
- \rho \left\langle  u_{i} u_{j} \right\rangle = \mu_{t} \left[ S_{ij} - \frac{1}{3} S_{kk} \delta_{ij} \right]

where \mu_{t} is the coefficient termed turbulence "viscosity" (also called the eddy viscosity), and S_{ij} is the mean strain rate defined by:

 
S_{ij}= \frac{1}{2} \left[ \frac{\partial U_{i}}{\partial x_{j}} + \frac{\partial U_{j}}{\partial x_{i}} \right]

This linear relationship is also known as the Boussinesq hypothesis. For a deep discussion on this linear constitutive relationship, check section Introduction to turbulence/Reynolds averaged equations.

My wiki