CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > CONVERGE

Converge CFD - Law of wall vs No slip

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

LinkBack Thread Tools Search this Thread Display Modes
Old   April 29, 2020, 06:21
Default Converge CFD - Law of wall vs No slip
New Member
Join Date: Apr 2020
Posts: 1
Rep Power: 0
Alan Nyqvist is on a distinguished road
Hey Guys,

Converge CFD offers the option to choose from slip, no slip and law of wall.

Other solvers like openfoam, ansys fluent and starccm only have the options of no slip or slip. Now, given that these software apply wall functions for the turbulence parameters, why does Converge have an option to use wall functions for velocity too?

I have tried 2 validation studies, Ahmed Body and a circular to rectangular transition duct, both of which can be found in the ercoftac database. Both of these studies gave good results when the wall was set to no slip as opposed to law of wall. y+ for the Ahmed body was around 120 and for the transition duct, it was 35 with the wall functions applied at the turbulence model instead.

I just wanted to know if there was any reason to use law of wall in the wall boundary condition since the results were not up to the mark.
Alan Nyqvist is offline   Reply With Quote

Old   May 1, 2020, 11:52
Default Converge CFD - Law of wall vs No slip
ywang89's Avatar
Yunliang Wang
Join Date: Dec 2015
Location: Convergent Science, Madison WI
Posts: 54
Rep Power: 6
ywang89 is on a distinguished road
A wall function is needed for all the softwares unless you can resolve the near wall region, which means your yplus should be less than 1.
Yunliang Wang
Applications Manager

ywang89 is offline   Reply With Quote

Old   June 12, 2020, 04:05
Homayoon sohrabi
Join Date: May 2020
Posts: 56
Rep Power: 2
homay95 is on a distinguished road
I have written a UDF code for velocity slip boundary condition, my UDF works properly for slip lenght equal to 1 micrometer, but when i apply slip lenght 20 micrometer, my calculation diverges and says "divergence in AMG" and "floating point exception". how can i get rid of them??
thanks in advance
homay95 is offline   Reply With Quote


converge cfd

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
decomposePar problem: Cell 0contains face labels out of range vaina74 OpenFOAM Pre-Processing 37 July 20, 2020 05:38
comsol: use general slip condition on the external slip wall sobhan.f Main CFD Forum 0 April 30, 2015 06:16
having trouble implementing airfoil with Wall Slip condition Khozaei4000 FLUENT 1 December 22, 2014 12:30
the law of the wall for rough surface maximus Main CFD Forum 0 January 31, 2004 08:45
turbulence wall law on unstructred mesh Quain Tchew Main CFD Forum 4 March 20, 2002 09:50

All times are GMT -4. The time now is 21:47.