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-   -   QSOR together with radiation (http://www.cfd-online.com/Forums/cd-adapco/52872-qsor-together-radiation.html)

Ossi April 2, 2002 03:03

QSOR together with radiation
 
I have simulated engine combustion and the heat from combustion is in variable QSOR (in the info file). Now, I am also icluding radiation modeling and that seems to change QSOR also ? I though that QSOR is strictly the heat from combustion but it seems that something else is also added to it when radiation is included ? Does anybody know how does radiation affect the computation of QSOR ?


daniel April 2, 2002 05:39

Re: QSOR together with radiation
 
It depends on your definition of QSOR, but if your'e using the subroutine from Adapco - this calculates the heat release a-posteriori, rather than the chemical heat of combustion, and includes radiation or any other heat source.

Ossi April 2, 2002 05:54

Re: QSOR together with radiation
 
I use my own coding for the combustion model (reacfn.f, an Eddy Break Up-type of a model). I also use the static, thermal enthalpy option. I wonder if it is somehow possible to extract the radiation part of the source term out from the QSOR ?

daniel April 2, 2002 06:11

Re: QSOR together with radiation
 
I did not quite understand where you define what QSOR is - is it in posdat.f? Anyway, if you calculate ther reaction rate in reacfn.f, why not just use the value you calculate there for the chemical rate?

Ossi April 2, 2002 06:18

Re: QSOR together with radiation
 
I do not define QSOR anywhere. STAR does that. And the problem with taking the heat out from the reacfn.f routine is that it is iterated, i.e. called many times during a time step. But indeed, maybe I can use posdat.f to extract the heat of combustion out (?) Let's see...

daniel April 2, 2002 06:42

Re: QSOR together with radiation
 
Why don't you extract the heat release just in the first iteration in every time step? reacfn.f receives the iteration number - use the ITER variable.

Ossi April 2, 2002 06:51

Re: QSOR together with radiation
 
Right, I could do that. (In principle, however, the first iteration result could still change quite a lot during the iteration process.) I will think about it.

daniel April 2, 2002 07:55

Re: QSOR together with radiation
 
another suggestion - define a "COMMON" variable in reacfn.f that would update after each iteration, and read it in the beginning of the next time step. good luck.


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