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

Black spots in filled contours

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

Reply
 
LinkBack Thread Tools Display Modes
Old   December 9, 2006, 14:34
Default Black spots in filled contours
  #1
Phil
Guest
 
Posts: n/a
Hey friends... I have come across a new problem today and was wondering if any of you have something similar. I was trying to plot filled contours of velocity profiles on a 2-D grid and found that there were two spopts symmetrical about my axis that were black! All the surrounding cells are colored differently (red and orange). My guess is that Fluent has made some numerical error and cannot display the data at that point. Does any one have any clues? PLots for other scalars like pressure and temperature are fine. Only velocity has a problem. You response is appreciated! Thanks, Phil
  Reply With Quote

Old   December 9, 2006, 15:36
Default Re: Black spots in filled contours
  #2
Bob
Guest
 
Posts: n/a
If you unchecked the "Auto Range" check box in Display->Contours to define your own range for velocity be sure you unchecked "Clip to Range" too. The black spots could be caused by values out-of-range. The spots will be coulored according with the highest (you said red so i think it could be "higher" otherwise it could be "lower") value of your range.

Bob
  Reply With Quote

Old   December 9, 2006, 18:22
Default Re: Black spots in filled contours
  #3
Phil
Guest
 
Posts: n/a
Actually I am getting the spots with the Auto Range option. I am not clipping my range.

This is what I don't understand. Thanks for the suggestion.

  Reply With Quote

Old   December 11, 2006, 05:01
Default Re: Black spots in filled contours
  #4
Ralf Schmidt
Guest
 
Posts: n/a
Hi!

That happend to me also, and I ended up with beliving it is a fluent graphics error.

Sorry, i found no way out (exept preprocessing of the graphic

Ralf
  Reply With Quote

Old   December 11, 2006, 14:03
Default Re: Black spots in filled contours
  #5
Phil
Guest
 
Posts: n/a
Thanks for your reply, Ralf.

I just noticed that the black spots are at different locations at different time steps!

  Reply With Quote

Old   December 11, 2006, 16:53
Default Re: Black spots in filled contours
  #6
Nak
Guest
 
Posts: n/a
I encountered a similar problem too: A black line is created sometimes on iso-surface that is genrated out of a 3D geometry. It gets displayed when I plot any contours on that iso-surface...!
  Reply With Quote

Old   December 12, 2006, 01:40
Default Re: Black spots in filled contours
  #7
JSM
Guest
 
Posts: n/a
Hello,

I also got the similar problem. When I am making the plane in 3D simulation, some places are looking like dark points. I think that it may happen in planes and 2D simulations. My guess is that may be graphical error.

with regards, JSM
  Reply With Quote

Old   December 12, 2006, 10:15
Default Re: Black spots in filled contours
  #8
Greg
Guest
 
Posts: n/a
sometimes i have black spots or black lines when i display contours but this is due to the activation of headlights and lightning method in display/options and display/lights. so try to disable these options if you activated them to display contours.

  Reply With Quote

Old   December 12, 2006, 14:07
Default Re: Black spots in filled contours
  #9
Phil
Guest
 
Posts: n/a
The black spots are present with or without lighting.

  Reply With Quote

Reply

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
2D, Can't Display Filled Contours. David FLUENT 6 September 24, 2012 04:21
zooming the pressure filled contours taran FLUENT 2 July 10, 2007 17:42
color contours with black line edges Anish FLUENT 2 March 28, 2007 01:02
Preconditioning and pressure contours ganesh Main CFD Forum 2 February 18, 2006 01:02
extension for liquid fraction contours venugopal FLUENT 0 June 11, 2004 01:27


All times are GMT -4. The time now is 10:42.