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-   -   Realizable k-epsilon in OpenFOAM (https://www.cfd-online.com/Forums/openfoam/74657-realizable-k-epsilon-openfoam.html)

vkrastev April 6, 2010 04:16

Realizable k-epsilon in OpenFOAM
 
Hi everybody, I have some questions about the realizable k-epsilon RANS model and its usage in OpenFOAM 1.6.x and I will be very pleased if someone could give me some explanation about it. So the questions are: 1) Is the realizable k-epsilon a Hi-Re RANS model? 2) Can it be used to directly solve the boundary layer in an external aerodynamics case? 3) In Fluent this model can be used with an "enhanced wall treatment" option: what this option actually represents? Can we use an equivalent or similar setting in OpenFOAM 1.6.x?

Thank you in advance

vkrastev April 6, 2010 08:49

Any replies?

bastil April 6, 2010 15:42

[QUOTE=vkrastev;2532881) Is the realizable k-epsilon a Hi-Re RANS model?[/QUOTE]
Yes.
Quote:

2) Can it be used to directly solve the boundary layer in an external aerodynamics case?
Since it is Hi-Re, no.
Quote:

3) In Fluent this model can be used with an "enhanced wall treatment" option: what this option actually represents? Can we use an equivalent or similar setting in OpenFOAM 1.6.x?
Not really.

vkrastev April 6, 2010 16:58

Thanks for the answer

alberto April 6, 2010 23:36

Quote:

Originally Posted by vkrastev (Post 253288)
In Fluent this model can be used with an "enhanced wall treatment" option: what this option actually represents? Can we use an equivalent or similar setting in OpenFOAM 1.6.x?

You have low-Re models in OpenFOAM which have been extensively validated in the scientific literature. Check the table at page U-98 of the User's guide.

Best,

vkrastev April 7, 2010 03:59

Quote:

Originally Posted by alberto (Post 253459)
You have low-Re models in OpenFOAM which have been extensively validated in the scientific literature. Check the table at page U-98 of the User's guide.

Best,

I know that there are some low-Re models (like the Launder-Sharma k-epsilon model), but i was just wondering which of them is the most suitable for solving an external aerodynamics case. By your knowledge of that kind of RANS models, is there any indication in the literature for their application in external aerodynamics? Anyway, thank you for the reply

Regards

FG_HSRM April 7, 2010 04:27

In the User- Guide is a long list of turbulence models and there are a lot of more not implemented.

Do anybody know where I can get a table with detailed Information about the models. Maybe a good book or link?

I'm looking for a model, that is valid for two phase gravitation drift flow through a bottle neck with venting through the same bottle neck.

Thanks in advance


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