[anubasu]

Hi guys,

I am using k-epsilon turbulence model in interFOAM. Currently my yPlus values range from min:2 to max: 400 with an average of 10 and changes with time. Will the yPlus value become constant as the simulation reaches steady state? I am simulating flow in a pipe. So what should be my ideal yPlus value? is it around 30 for k-e model?
Thanks.

[NotOverUnderated]

Assuming you're using the standard kEpsilon:

- You must use wall functions.
- Your yPlus must be greater than 30 and less than say 200 (this is not hard limit). Usually, your yPlus should be around 50 or 60.

[anubasu]

Originally Posted by NotOverUnderated

Assuming you're using the standard kEpsilon:

- You must use wall functions.
- Your yPlus must be greater than 30 and less than say 200 (this is not hard limit). Usually, your yPlus should be around 50 or 60.

Hi , I am using the default ke model in Openfoam and the BCs defaultly available in 0 dir in OpenFOAM. Is this fine?

[saeed jamshidi]

Hi anubasu,
Let me add somthing to this thread.

For the cases you are going to use k-epsilon turbulence model you should use wall functions in which y-pluse belongs to the logarithmic region, because k-epsilon turbulence model isn't accurate just near the wall due to some assumtions in order to evaluate this model constant numbers;
Screenshot (241).png & Screenshot (240).png

Besides, each tutorial has introduced delibrately in order to convey a message and purpuse. For example, I have seen motorbike case in both simpleFoam and pisoFoam. You can develope and use tutorials based on your requirement.
However, the contents of the tutorials are correct.