[saeed jamshidi]

Hi all, hope you are doing well.

I'm going to use k-omega sst turbulence model in openfoam. I have noticed that we should consider y+=1 for this model, which first cell center falls in viscous sub-layer. However, I looked at some tutorials in openfoam and I saw this part as K boundary condition:

wall
    {
        type            kqRWallFunction;
        value           $internalField;
    }

why wall function is used as turbulent kinetic wall BC?! while we are considering y+=1 for this model!!!
It should not be as Calculated type?!
It is similar for omega and nut!

wall
    {
        type            omegaWallFunction;
        value           $internalField;
    }

wall
    {
        type            nutkWallFunction;
        value           uniform 0;
    }

thanks.

[saeed jamshidi]

Any idea would be appreciated?

[Wowbagger]

Hi Saeed,

please have a look to this document which described how to resolve boundary layer in open foam:
http://www.wolfdynamics.com/training...e_2021_OF8.pdf
Especially chapter 6 with a good summary on page 323.

I suggest that the definition "...WallFunction" is related to some historical development.
If someone knows more about this - I would like to know too.

Best regards
Michael

[saeed jamshidi]

Dear Wowbagger, thank for the reply.

It looks like a nice source, I will go through it and share my findings.

Best regards,
Saeed