# Problem when adding temperature to interFoam

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 November 2, 2012, 00:58 Problem when adding temperature to interFoam #1 Member   HouKen Join Date: Jul 2011 Posts: 67 Rep Power: 13 Hi foamers! I tried to apply temperature calculation to interFoam according to the hot thread: http://www.cfd-online.com/Forums/ope...interfoam.html And what I did was exactly same with the author "ovie" wrote in the #14 reply to the above thread. Everything compiled well, however when I run it on a two-phase flow case, temperature results near interface was higher than heat source temperature which is surely not reliable result. Also I test the modified solver to solve for single phase heat transfer calculation, although I didnot do precise validation, temperature field seems to be reasonable. Thus I think the main problem here lies in the interface. On the other hand, from a theoretical view, no matter interface properties(cp, Pr...) is linear interpolated or harmonic interpolated, interface temperature should be no higher than phase temperature surrounding it. I cant figure out what is the reason for this problem, plz help! (Also I am trying to debug it by output cp and other properties on the fly, but I am not sure how to do it elegantly, directly to the console or paraView, plz help ...)

 November 4, 2012, 23:10 #2 Member   HouKen Join Date: Jul 2011 Posts: 67 Rep Power: 13 I read the thread post by "ovie" again, and I do find that move the Cp to RHS (i.e., now the TEqn becomes: fvScalarMatrix TEqn ( fvm::ddt(rho, T) + fvm::div(rhoPhi, T) - fvm::laplacian((kappa/Cp), T) ); )help the convergence. But from a theoretical view, I believe it's mathematically equal. So I got even more confused, I think there must be sth. I misunderstood/didn't understood in the whole process. plz help!

 November 5, 2012, 00:29 #3 Senior Member   Nima Samkhaniani Join Date: Sep 2009 Location: Tehran, Iran Posts: 1,265 Blog Entries: 1 Rep Power: 23 , i guess it returns to the sensitivity of numerical procedure to calculation of convection terms (flux), those are mathematical the same on the whole domain except at interface but at interface they are a little different, and it can be accepted a new model __________________ Telegram channel (https://telegram.me/openfoam4Iranian) My Weblog in Persian(http://openfoam.blogfa.com/) My Personal Website (http://nimasamkhaniani.ir/)

November 5, 2012, 01:06
#4
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HouKen
Join Date: Jul 2011
Posts: 67
Rep Power: 13
Quote:
 Originally Posted by nimasam , i guess it returns to the sensitivity of numerical procedure to calculation of convection terms (flux), those are mathematical the same on the whole domain except at interface but at interface they are a little different, and it can be accepted a new model
Could you be a little bit more explicit on the difference of the interface.(or where can I find related information)
Basically I have only read Patankar and Versteeg's book on cfd and both these books didn't focus much on detailed numerical scheme.
(Another newbie question: I want to output Cp in order to see the space distribution of it(just like T and alpha), how can I do it? plz help!)

 November 5, 2012, 02:35 #5 Senior Member   Nima Samkhaniani Join Date: Sep 2009 Location: Tehran, Iran Posts: 1,265 Blog Entries: 1 Rep Power: 23 if you want to see Cp just define a volScalarField like T in "creatFields.H" __________________ Telegram channel (https://telegram.me/openfoam4Iranian) My Weblog in Persian(http://openfoam.blogfa.com/) My Personal Website (http://nimasamkhaniani.ir/)