CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

Oscillation (losing stability) ---> unsteady flow?

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

LinkBack Thread Tools Display Modes
Old   February 25, 2004, 10:46
Default Oscillation (losing stability) ---> unsteady flow?
Posts: n/a
In calculaiton using an unsteady approach, do oscillations (odd-even oscillations, look like losing stability) imply that an unsteady flow is going to happen? If yes, how to pull out the correct unsteady solution?

Thanks for your point of view or clues for references.

  Reply With Quote

Old   February 25, 2004, 13:29
Default Re: Oscillation (losing stability) ---> unsteady f
Posts: n/a
Oscillations do not necessarily imply the advent of an unsteady flow. You need to make sure that your loss of "stability" is not a numerical issue. If your algorithm is stable numerically then you can begin to address issues such as numerical damping that can kill a non-steady solution. But if you are picking up odd-even oscillations it sounds to me as if you have a decoupling phenomenon occurring, which is not realistic but a problem with your numerics. Until you fix it you aren't going to be able to get a correct solution.
  Reply With Quote


Thread Tools
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 On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Airfoil conditions for unsteady flow Dave Main CFD Forum 3 April 24, 2008 17:11
how to predict unsteady flow from case definition? Felix Main CFD Forum 6 August 28, 2007 16:40
Outlet boundary conditions for unsteady flow Bjorn B Main CFD Forum 3 January 11, 2006 06:42
computation about flow around a yawed cone Tylor Xie Main CFD Forum 0 June 9, 1999 07:33
Initial Conditions in unsteady turbulent flow Z. Zeng Main CFD Forum 5 April 28, 1999 17:38

All times are GMT -4. The time now is 11:13.