CFD Online Logo CFD Online URL
Home > Forums > ANSYS

Statistic averaging and Periodic BC Fluent/Gambit

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

LinkBack Thread Tools Display Modes
Old   July 5, 2011, 18:55
Default LES Statistic averaging and Periodic BC Fluent/Gambit
Senior Member
truffaldino's Avatar
Join Date: Jan 2011
Posts: 248
Blog Entries: 5
Rep Power: 10
truffaldino is on a distinguished road

I am running LES with FLUENT for a wing: basically this is 2D x-y-airfoil translated by 0.2 of its chord in z-direction with periodic BC imposed in z-direction.

After gathering statistics I got this strange averaged plot of Cp(x): there are some strange spikes at the sucion side closer to the trailing edge
(as you could see on the image attached).

It seems to me that it is not physics at the origin of tese spikes, but some software problems.

I had troubles to make periodic mesh with GAMBIT using automatic boundary layer generation, but then repared periodic conditions with help of FLUENT:

Might it happen that this "reparation" was not complete? It is seen on the plot that spikes occur once at each cell/or perhaps between cells on cell faces.

On the other hand, I have these spikes only on a part of airfoil where separation/transition and big fluctuations occur,
so it might be also problem of statistic averaging.

I will be grateful for your help.

Attached Images
File Type: jpg Cp.jpg (12.3 KB, 7 views)

Last edited by truffaldino; July 7, 2011 at 06:43.
truffaldino is offline   Reply With Quote


les, les grid, periodic bc, statistics

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
export time steps for ensemble averaging Thomas Baumann Siemens 0 March 2, 2010 04:19
Averaging field over a spatial direction fs82 OpenFOAM 10 August 12, 2009 10:44

All times are GMT -4. The time now is 14:23.