CFD Online Discussion Forums

CFD Online Discussion Forums (
-   OpenFOAM Running, Solving & CFD (
-   -   Favre averaged values (

chris1980 June 22, 2006 09:27

I want to do RANS with variabl
I want to do RANS with variable density. The governing equations for my problem known but I was wondering how to treat the favre averaged values!

- Are the variables automatically favre averaged when using a compressible RANS-model?

- When the solver computes i.e. k,epsilon ... are these the Favre averged values which I get back?

As you can see I am a little bit confused with these averaging things.

grtabor June 22, 2006 10:13

Yes, and yes. The point of
Yes, and yes.

The point of Favre averaging is that it is a mathematical trick designed to get us back to the same form of the equations. We _know_ how to solve the NSE in the form

ddt(rho u) + div(rho u u) = ...

When we average this equation /\ we get

ddt(/rho u \) + ....

Favre averaging allows us to split /rho u\ into separate variables, getting back to where we started again. So, yes; when using a compressible RANS model, the variables will be by definition assumed to be Favre averaged.


ayannath23 July 14, 2012 21:29

Favre or RANS averaged equations are used in incompresible reacting flow ?
I'm simulating incompresible reacting flow case where RSM is used as turbulence model. I have doubt about what fluent is actually solving for my case. Whether Favre-averaged NSE or RANS averaged NSE.

Can anybody help ?

All times are GMT -4. The time now is 12:57.