CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Wiki > Near-wall treatment for k-omega models

Near-wall treatment for k-omega models

From CFD-Wiki

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
From the Fluent manual:<br>
 
-
 
Both k- omega models (std and sst) are available as low-Reynolds-number models as well as high-Reynolds-number models. <br>
Both k- omega models (std and sst) are available as low-Reynolds-number models as well as high-Reynolds-number models. <br>
Line 16: Line 14:
If '''Transitional Flows option is not active''', then the mesh guidelines should be the same as for the wall functions.<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.)''
''(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>

Revision as of 10:28, 18 May 2006

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 desirabl.)


Reference: FLUENT 6.2 Documentation, 2006

My wiki