Scalable wall function

[bernardombraga]

High Re-number k-epsilon turbulence models (e.g. standard k-epsilon or RNG) are just valid if they are used along with wall function in the log-law regime (Yplus > 30). When Yplus < 30, the log wal becomes progressively invalid. Besides, these models perform poorly if the laminar sublayer is solved (Uplus = Yplus).

A simple turnaround for this issue is to adopt a scalable wall function like it is used in Ansys CFD software (i.e. the Yplus is limited by the value 11 and the log law is always used). For further details, see section 9.3.2 of "Best Practice: RANS Turbulence Modeling in Ansys CFD": https://www.ansys.com/resource-center/technical-paper/best-practice-rans-turbulence-modeling-in-ansys-cfd

So, a useful new feature would be to implement the scalable wall function for these models. Then, the user could choose between standard wall function or the scalable wall function.

[kdg5424]

Hello @bernardombraga. This is Donggyu from NEXTFOAM.
Thank you for your interest in BARAM.

We also consider your suggestion and also Scalable wall function is on the development list.
But it's not priority-high.
If it is implemented, I'll let you know.

Best Regards

Donggyu Kim

[bernardombraga]

Hello Donggyu , thank you!