CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > ANSYS > FLUENT

Spalart-Allmaras model in Ansys Fluent 12.0 theory guide

Register Blogs Members List Search Today's Posts Mark Forums Read

Like Tree1Likes
  • 1 Post By macfly

LinkBack Thread Tools Search this Thread Display Modes
Old   February 7, 2010, 17:03
Default Spalart-Allmaras model in Ansys Fluent 12.0 theory guide
Senior Member
François Grégoire
Join Date: Jan 2010
Location: Canada
Posts: 392
Rep Power: 17
macfly is on a distinguished road
From Theory guide, chapter 4:

4.3.7 Wall Boundary Conditions

When the mesh is fine enough to resolve the viscosity-dominated sublayer, the wall shear stress is obtained from the laminar stress-strain relationship: (4.3-16)

If the mesh is too coarse to resolve the viscous sublayer, then it is assumed that the centroid of the wall-adjacent cell falls within the logarithmic region of the boundary layer, and the law-of-the-wall is employed: (4.3-17)

At what y+ Fluent does the switch??? It's not clear here. Is it at y+>11.225 as explained for Standard Wall Functions in section 4.12.2 of Theory guide?

Thanks in advance,

From Theory guide, chapter 12:

12.13.8 Low-Re Damping
If either of the Spalart-Allmaras or the Spalart-Allmaras Detached Eddy Simulation models are used, you may enable a low-Reynolds damping to the turbulent viscosity by enabling the Low-Re Damping option under Spalart-Allmaras Options in the Viscous Model dialog box.

This only tells me that I can activate Low-Re damping by activating Low-Re damping... Does anyone know what consequence has this Low-Re damping?
rasoulb likes this.
macfly is offline   Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Superlinear speedup in OpenFOAM 13 msrinath80 OpenFOAM Running, Solving & CFD 18 March 3, 2015 05:36
A few questions about Spalart Allmaras model and y seb62 OpenFOAM Running, Solving & CFD 8 January 15, 2011 13:09
Reynolds Stress model in CFX vs Fluent Tim CFX 1 October 7, 2009 06:19
Numerical integration of Spalart Allmaras turbulence model RenardP Main CFD Forum 0 June 11, 2009 14:53
extracting K and Epsilon from Spalart Allmaras Sundar Main CFD Forum 4 July 31, 2006 02:02

All times are GMT -4. The time now is 20:43.