CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > SU2

How to simulate more shedding cycles of the unsteady NACA0012 flow?

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 3, 2021, 12:16
Default How to simulate more shedding cycles of the unsteady NACA0012 flow?
  #1
New Member
 
Avinash Arun
Join Date: Aug 2021
Posts: 5
Rep Power: 5
A Arun is on a distinguished road
I have been trying to simulate the unsteady flow over naca 0012 airfoil. The simulation converges and stops after 1 shedding cycle. I wish to simulate for more cycles how can I do that ?
I have attached the configuration file here.
Attached Files
File Type: txt unsteady_naca0012.txt (6.9 KB, 9 views)
A Arun is offline   Reply With Quote

Old   August 3, 2021, 17:25
Default
  #2
Senior Member
 
Wally Maier
Join Date: Apr 2019
Posts: 123
Rep Power: 7
wallym is on a distinguished road
Hi A Arun,

Thanks for your question. I dont have a ton of experience in unsteady flows, but I would suggest increasing your TIME_ITER field to something longer. If the simulation is kicking out before then, you could make your convergence fields more stringent, i.e. RESIDUAL_MINVAL=-8 instead of -3. (Not sure on this one).

Let us know if that works,
Wally
wallym is offline   Reply With Quote

Old   August 4, 2021, 03:08
Default
  #3
New Member
 
Avinash Arun
Join Date: Aug 2021
Posts: 5
Rep Power: 5
A Arun is on a distinguished road
Hi Wallym,

Thanks for the reply. In this simulation changing the convergence criteria does simulate for a longer time but not for more shedding cycles. (Like the simulation is stretched ). Changing TIME_ITER also does not reflect any change. I tried changing almost every value but im not able to simulate for more shedding cycles. I even deleted the convergence criteria.
A Arun is offline   Reply With Quote

Old   August 4, 2021, 13:30
Default
  #4
Senior Member
 
Wally Maier
Join Date: Apr 2019
Posts: 123
Rep Power: 7
wallym is on a distinguished road
Hmmmm,
How about increasing the MAX_TIME option?
wallym is offline   Reply With Quote

Old   August 5, 2021, 05:37
Default
  #5
New Member
 
Avinash Arun
Join Date: Aug 2021
Posts: 5
Rep Power: 5
A Arun is on a distinguished road
tried that too. okay so one thing that I noticed is that it is definitely simulating for a longer period but when I use paraview to visualize the simulation the simulation stops after one shedding cycle and the remaining output files are just dummy
A Arun is offline   Reply With Quote

Old   August 7, 2021, 07:13
Default
  #6
Member
 
Ravi
Join Date: May 2017
Posts: 32
Rep Power: 9
raviramesh10 is on a distinguished road
Quote:
Originally Posted by A Arun View Post
Hi Wallym,

Thanks for the reply. In this simulation changing the convergence criteria does simulate for a longer time but not for more shedding cycles. (Like the simulation is stretched ). Changing TIME_ITER also does not reflect any change. I tried changing almost every value but im not able to simulate for more shedding cycles. I even deleted the convergence criteria.
Hi Arun,

Did you try to change the time step? It is possible that the issue would be related to the inability of the code to identify the shedding cycles as they do not correspond to the vortex shedding frequency.

Hope that helps.

Ravi
raviramesh10 is offline   Reply With Quote

Old   August 7, 2021, 15:31
Default
  #7
New Member
 
Avinash Arun
Join Date: Aug 2021
Posts: 5
Rep Power: 5
A Arun is on a distinguished road
Hi Ravi,
Thanks for the reply but changing time steps does not have any effect the simulation runs for as long as I want but when I visualize the flow field it stops after a certain point showing no change whatsoever.
A Arun is offline   Reply With Quote

Old   May 18, 2022, 21:34
Default
  #8
New Member
 
Guangnan Jia
Join Date: Oct 2021
Posts: 5
Rep Power: 5
Gj419 is on a distinguished road
Quote:
Originally Posted by A Arun View Post
I have been trying to simulate the unsteady flow over naca 0012 airfoil. The simulation converges and stops after 1 shedding cycle. I wish to simulate for more cycles how can I do that ?
I have attached the configuration file here.
Hi, Arun. Have you solved this problem yet? I faced the same problem as you now. Thanks for reply
Gj419 is offline   Reply With Quote

Reply


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
About Some Concepts:Laminar flow, turbulent flow, steady flow and time-dependent flow Jing Main CFD Forum 8 October 5, 2018 18:02
Unsteady - Multiphase flow - No Vortex Shedding Aarthy Meena Main CFD Forum 0 February 5, 2016 01:45
use sliding mesh to simulate unsteady flow annie FLUENT 3 November 9, 2004 08:48
Unsteady AND Steady mode for Fully Developped Flow Dominique FLUENT 5 April 16, 2004 18:58
About unsteady flow simulation Ji Fidelity CFD 3 June 10, 2003 11:04


All times are GMT -4. The time now is 12:48.