CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

Rough wall function vs. atmospheric rough wall function

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

Like Tree1Likes
  • 1 Post By joshm

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 23, 2015, 06:30
Default Rough wall function vs. atmospheric rough wall function
  #1
New Member
 
Josh
Join Date: Jun 2013
Posts: 19
Rep Power: 9
joshm is on a distinguished road
I have been looking into homogeneity of atmospheric boundary layer profiles through an empty fetch. I noticed that nutkAtmRoughWallFunction performed slightly worse than nutkRoughWallFunction.

When looking at the code to work out what the atmospheric version was doing, I came across a definition I can't work out:

As expected, both define effective viscosity as:


For nutkRoughWallFunction, E' is defined as expected, based on roughness regime. For fully rough (most practical ABL applications), it's:

However, for the nutkAtmRoughWallFunction, it is defined as:
.

I've not seen this definition in the literature, and can't work out why it's used. It means that the sand grain roughness is never defined in the equation, which seems odd.

Can anyone shed any light on this?
phuchuynh likes this.
joshm is offline   Reply With Quote

Old   February 27, 2016, 08:12
Default
  #2
Senior Member
 
Mojtaba.a's Avatar
 
Mojtaba Amiraslanpour
Join Date: Jun 2011
Location: Zanjan, Iran
Posts: 306
Rep Power: 12
Mojtaba.a is on a distinguished road
Send a message via Skype™ to Mojtaba.a
Hi,
I am working on the same. I can't see the expressions you provided. I have some improves regarding the papers I have reviewed until now.
__________________
Learn OpenFOAM in Persian
SFO (StarCCM+ FLUENT OpenFOAM) Project Team Member
Complex Heat & Flow Simulation Research Group
If you can't explain it simply, you don't understand it well enough. "Richard Feynman"
Mojtaba.a is offline   Reply With Quote

Old   February 6, 2020, 09:32
Default
  #3
HPE
Senior Member
 
Herpes Free Engineer
Join Date: Sep 2019
Location: The Home Under The Ground with the Lost Boys
Posts: 658
Rep Power: 8
HPE is on a distinguished road
The last equation corresponds to Eq. 5 from

Hargreaves, D. M., & Wright, N. G. (2007).
On the use of the kε model in commercial CFD software to model
the neutral atmospheric boundary layer.
Journal of wind engineering and industrial aerodynamics, 95(5), 355-369.
DOI:10.1016/j.jweia.2006.08.00
HPE is offline   Reply With Quote

Reply

Tags
boundary layer, k-epsilon, wall functions

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
[Other] refineWallLayer Error Yuby OpenFOAM Meshing & Mesh Conversion 1 May 19, 2017 10:13
[blockMesh] Errors during blockMesh meshing Madeleine P. Vincent OpenFOAM Meshing & Mesh Conversion 51 May 30, 2016 10:51
Standard wall function - breakdown - rough wall Marsoup FLUENT 0 August 1, 2014 16:13
Error with Wmake skabilan OpenFOAM Installation 3 July 28, 2009 00:35
Problem with rhoSimpleFoam matteo_gautero OpenFOAM Running, Solving & CFD 0 February 28, 2008 06:51


All times are GMT -4. The time now is 16:22.