CFD Online Discussion Forums - Strange behaviour in a thermalBaffle with radiation

Hi everybody!

It's been a while since tha last thread I opened here, I hope nobody missed me too much... Otherwise, I'm back anyway!

Well...Let's stick to the point! I have a web site where I am trying to do a kind of user's guide for beginners with some very basic tutorials explained and detailed in order to make them the most clear and understandable I can. A couple of days ago I was preparing a tutorial based on the circuitBoardCooling tutorial but readapted in order to account only for radiation. I talked about this case some months ago in the thread below

possible-bug-fvdom-when-odd-number-ntheta-used

However, in that thread I modified the geometry so that the case was only made up of baffles of the type thermalBaffle1D because I used to have some trouble with the 3D thermal baffles. Now (that I'm older and wiser :D ) I finally got the case working with 3D baffles (I did a very dumb mistake in the past...), thus, I wanted to upload the case to my web site with the possibility to use them. Here you can find the final test case and the explanation of all the modifications I did:

circuitBoardCooling_rad

And now, here comes the problem! When running the case with 1D baffles the results seem to be reasonable, I mean, a thermal distribution in the baffle that receives the radiation exist. However, when I run the same case but beeing the baffle that receive the radiation a 3D baffle everything goes away... the temperature at the end of the simulation is constant all along the baffle (but different from the initial value!). I attach the pictures of the residual plots.

Residual plot of the case when the baffle is 1D

http://www.cfd-online.com/Forums/att...1&d=1461611887

Residual plot of the case when the baffle is 3D

http://www.cfd-online.com/Forums/att...1&d=1461611887

Residual plot of the 3D baffle region

http://www.cfd-online.com/Forums/att...1&d=1461611887

I apologize for the size of the pictures, I don't know how to resize them... If someone lets me know how to do that I will edit the post to fix it!

And regarding the problem with the simulation, can anyone tell me what is wrong with the run? Am I doing something wrong? Is there a bug with the 3D thermal baffles when it comes to calculate the radiative contribution?

Many thanks in advance!

Best regards,

Alex