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boundaryWallFunctionsProfile Tutorial yPlus / wall functions

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Old   February 8, 2017, 15:18
Question boundaryWallFunctionsProfile Tutorial yPlus / wall functions
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RK_Token
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Hallo,


I‘m trying to understand the „boundaryWallFunctionsProfile“ tutorial, in the way how the wall functions are being handled by OpenFOAM for the different yPlus (y+) values.

As far as I have understand, if y+ <= 1 (or 5) no wall function is needed and for y+>= 30 wall functions have to be applied. Further more its not recommended to run simulations with y+ within the buffer-layer region (5 < y+ < 30).

So now if I check the output of the tutorial, we get proper u+ values for y+ values within all three regions, beside a wall-function (nutkWallFunction) was defined within the 0/nut file.

My assumption would be to get bad results for small y+.


So Is OpenFoam ignoring wall-functions if y+ is smaller than 30, or is some blending going on?


Thank you and best regards.


related topics.

Wall treatment with OpenFOAM

Wall function usage
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Old   February 17, 2021, 08:13
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Arijit Saha
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Quote:
Originally Posted by RK_Token View Post
Hallo,


I‘m trying to understand the „boundaryWallFunctionsProfile“ tutorial, in the way how the wall functions are being handled by OpenFOAM for the different yPlus (y+) values.

As far as I have understand, if y+ <= 1 (or 5) no wall function is needed and for y+>= 30 wall functions have to be applied. Further more its not recommended to run simulations with y+ within the buffer-layer region (5 < y+ < 30).

So now if I check the output of the tutorial, we get proper u+ values for y+ values within all three regions, beside a wall-function (nutkWallFunction) was defined within the 0/nut file.

My assumption would be to get bad results for small y+.


So Is OpenFoam ignoring wall-functions if y+ is smaller than 30, or is some blending going on?


Thank you and best regards.


related topics.

Wall treatment with OpenFOAM

Wall function usage
Hello RK, I m not a profound user of Openfoam who can certainly help you with this issue. But was just curious if I can use this script to plot the y+ vs u+ graph for any other solver or not. If you have any idea could you please share how can I compile this with a pimpleFoam solver?
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