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-   -   Turbulent eddy diffusivity for mixing?? (https://www.cfd-online.com/Forums/main/3271-turbulent-eddy-diffusivity-mixing.html)

Ray March 22, 2001 05:07

Turbulent eddy diffusivity for mixing??
 
Hi,

In turbulent mixing, an eddy diffusivity is usually used to study the mixing. But when the flow is laminar and unsteady, instabilities present in the system,which can also be used for mixing. In other words, there are also eddies in laminar flow. My question is if there is something like eddy diffusivity that can be used to describe the mixing in laminar usteady flow? if so, how to define it? say, I know the flow velocity field.

Many thanks!

Ray

Tian Jin November 5, 2020 08:18

Dear Ray,

Have you ever solved this problem? I also have the same question.

Tian Jin

FMDenaro November 5, 2020 10:28

Quote:

Originally Posted by Tian Jin (Post 786852)
Dear Ray,

Have you ever solved this problem? I also have the same question.

Tian Jin

This issue is well suited for the use of LES formulation with a dynamic SGS model.

Tian Jin November 5, 2020 11:57

Do you mean that when we use the dynamic SGS model in OpenFoam, we can apply it to both eddy viscosity and eddy diffusivity?


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