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

Reason for asymmetry in symmetric geometries

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

LinkBack Thread Tools Display Modes
Old   June 10, 2010, 02:20
Default Reason for asymmetry in symmetric geometries
Senior Member
Join Date: Nov 2009
Location: Michigan
Posts: 135
Rep Power: 7
doubtsincfd is on a distinguished road
say I have a symmetric geometry like a circular cylinder. the grid is perfectly symmetric around the cylinder and the inlet profile is also symmetric. still why do we get alternate vortex shedding? what is the numerical reason?

in real life scenario there is some asymmetry in the inlet flow which might trigger the asymmetric vortex shedding. but why does this happen in a perfect cfd simulation?
doubtsincfd is offline   Reply With Quote

Old   June 10, 2010, 08:13
Senior Member
Join Date: Jul 2009
Posts: 191
Rep Power: 8
agd is on a distinguished road
It is true that in real life there may be some asymmetry that can trigger an asymmetry in a flow, which might not happen in a "perfectly" symmetric CFD simulation. But no CFD simulation is perfectly symmetric, due to such things as round-off error. Also, you are failing to consider the possibility that the Navier-Stokes equations can support solutions that are time-varying and only symmetric in a time-averaged sense.
agd is offline   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
Discussion: Reason of Turbulence!! Wen Long Main CFD Forum 3 May 15, 2009 09:52
Why is the solution not symmetric? Hp FLUENT 0 February 2, 2007 15:47
symmetric flow around fuselage Christoph FLUENT 0 November 3, 2005 06:50
Gambit - Virtual Geometries (Pro's & Con's) James Date FLUENT 3 August 11, 2003 15:46
Symmetric problem - Assymetric results Mark Phoenics 2 July 2, 2001 09:04

All times are GMT -4. The time now is 18:05.