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-   -   Black spots in filled contours (http://www.cfd-online.com/Forums/fluent/43080-black-spots-filled-contours.html)

Phil December 9, 2006 14:34

Black spots in filled contours
 
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

Bob December 9, 2006 15:36

Re: Black spots in filled contours
 
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

Phil December 9, 2006 18:22

Re: Black spots in filled contours
 
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.


Ralf Schmidt December 11, 2006 05:01

Re: Black spots in filled contours
 
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

Phil December 11, 2006 14:03

Re: Black spots in filled contours
 
Thanks for your reply, Ralf.

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


Nak December 11, 2006 16:53

Re: Black spots in filled contours
 
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...!

JSM December 12, 2006 01:40

Re: Black spots in filled contours
 
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

Greg December 12, 2006 10:15

Re: Black spots in filled contours
 
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.


Phil December 12, 2006 14:07

Re: Black spots in filled contours
 
The black spots are present with or without lighting.



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