Near-wall treatment for k-omega models

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

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. <br>

This means that all boundary conditions for <br>
- '''wall-function meshes''' will correspond to the wall function approach, while for the <br>
- '''fine meshes''', the appropriate low-Reynolds-number boundary conditions will be applied. <br>

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 <br>
''(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).)''<br>

If '''Transitional Flows option is not active''', then the mesh guidelines should be the same as for the wall functions.<br>
''(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 desirabl.)''

<br>

Reference: 
FLUENT 6.2 Documentation, 2006 <br>