CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > General Forums > Main CFD Forum

Near Wall Courant Numbers

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

Like Tree1Likes
  • 1 Post By FMDenaro

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 26, 2020, 09:45
Default Near Wall Courant Numbers
  #1
New Member
 
Joćo V. M. Andreotti
Join Date: May 2020
Posts: 2
Rep Power: 0
JAndreotti is on a distinguished road
I'm trying to simulate the dynamic stall of a wing and due to the boundary layer refinements I'm getting very high courant numbers near the walls. The courant numbers for the rest of the flow seem to be ok (< 1). So, is it acceptable under these circumstances to have high courant numbers? And, for this application, what is a good criterion to set the time-step (I'm only interested in the large periodic oscillations in lift and drag)?
JAndreotti is offline   Reply With Quote

Old   May 26, 2020, 10:58
Default
  #2
Senior Member
 
Filippo Maria Denaro
Join Date: Jul 2010
Posts: 5,693
Rep Power: 60
FMDenaro has a spectacular aura aboutFMDenaro has a spectacular aura aboutFMDenaro has a spectacular aura about
Quote:
Originally Posted by JAndreotti View Post
I'm trying to simulate the dynamic stall of a wing and due to the boundary layer refinements I'm getting very high courant numbers near the walls. The courant numbers for the rest of the flow seem to be ok (< 1). So, is it acceptable under these circumstances to have high courant numbers? And, for this application, what is a good criterion to set the time-step (I'm only interested in the large periodic oscillations in lift and drag)?

That sounds very strange, close to a wall the turbulent boundary layer is mainly governed by the viscous sub-layer. The cfl should be small.
aero_head likes this.
FMDenaro is offline   Reply With Quote

Reply

Tags
courant, courant number, implicit unsteady, stall, time advancement

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
Divergence in AMG solver! marina FLUENT 20 August 1, 2020 11:30
Courant Number waseeqsiddiqui FLUENT 3 December 27, 2018 10:43
Enhanced Wall Treatment paduchev FLUENT 24 January 8, 2018 11:55
Difficulty In Setting Boundary Conditions Moinul Haque CFX 4 November 25, 2014 17:30
Radiation interface hinca CFX 15 January 26, 2014 17:11


All times are GMT -4. The time now is 15:54.