# Linear eddy viscosity models

### From CFD-Wiki

(Difference between revisions)

m |
|||

Line 1: | Line 1: | ||

+ | {{Turbulence modeling}} | ||

+ | |||

These are turbulence models in which the [[Introduction to turbulence/Reynolds averaged equations|Reynolds stresses]] as obtained from a [[Introduction to turbulence/Reynolds averaged equations|Reynolds averaging of the Navier-Stokes equations]] are modelled by a ''linear constitutive relationship'' with the ''mean'' flow straining field, such as: | These are turbulence models in which the [[Introduction to turbulence/Reynolds averaged equations|Reynolds stresses]] as obtained from a [[Introduction to turbulence/Reynolds averaged equations|Reynolds averaging of the Navier-Stokes equations]] are modelled by a ''linear constitutive relationship'' with the ''mean'' flow straining field, such as: | ||

## Revision as of 17:17, 30 October 2009

These are turbulence models in which the Reynolds stresses as obtained from a Reynolds averaging of the Navier-Stokes equations are modelled by a *linear constitutive relationship* with the *mean* flow straining field, such as:

where is the coefficient termed turbulence "viscosity" (also called the eddy viscosity), and is the *mean* strain rate defined by:

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.