# Near-wall treatment for k-omega models

### From CFD-Wiki

Both k- omega models (std and sst) are available as low-Reynolds-number models as well as high-Reynolds-number models.

The wall boundary conditions for the k equation in the k- omega models are treated in the same way as the k equation is treated when enhanced wall treatments are used with the k- epsilon models.

This means that all boundary conditions for

- **wall-function meshes** will correspond to the wall function approach, while for the

- **fine meshes**, the appropriate low-Reynolds-number boundary conditions will be applied.

that means:

If the **Transitional Flows option is enabled **in the Viscous Model panel, low-Reynolds-number variants will be used, and, in that case, mesh guidelines should be the same as for the enhanced wall treatment

*(y+ at the wall-adjacent cell should be on the order of y+ = 1. However, a higher y+ is acceptable as long as it is well inside the viscous sublayer (y+ < 4 to 5).)*

If **Transitional Flows option is not active**, then the mesh guidelines should be the same as for the wall functions.

*(For [...] wall functions, each wall-adjacent cell's centroid should be located within the log-law layer, 30 < y+ < 300. A y+ value close to the lower bound y+ = 30 is most desirable.)*

Reference:
FLUENT 6.2 Documentation, 2006