CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   OpenFOAM Running, Solving & CFD (http://www.cfd-online.com/Forums/openfoam-solving/)
-   -   Implementation of PaSR model in OpenFOAM (http://www.cfd-online.com/Forums/openfoam-solving/92246-implementation-pasr-model-openfoam.html)

 Alish1984 September 7, 2011 10:50

Implementation of PaSR model in OpenFOAM

Hi Foamers

I have a question about PaSR in OF
as said in FabianPengKarrlhom PhD thesis "http://powerlab.fsb.hr/ped/kturbo/OpenFOAM/docs/ " in PaSR model the cells are divided into a reacting
part, and a non-reacting part. The reacting part is treated like a perfectly
stirred reactor, in which all present species are homogeneously mixed and
reacted. then reaction rates are computed and multiplied by a factor kappa (which stands for a turbulent mixing effects)

the equations in chemistryMoldel.C in "derivatives" function are
dp/dt=0
dc[i]/dt=omega{dot}[i]
dT/dt=-(Sigma(h[i]*omega{dot}[i]) )/(sigma(X[i]*Cp[i]))

these equation are used to evaluate reaction rates but these are not the perfectly stirred reactor governing equations.It seems we have assumption like
1-constant pressure
2-Constant volume
here, are they true assumptions for the cells?!

does any one know thw perfectly stirred reactor governing equations which mentioned in the FabianPengKarrlhom thesis?

 timaji September 10, 2011 12:08

hi ali

as turns "an introduction to combustion" said in computing reaction rate the effects of tempreature variations are stronger than pressure variations, so the constant pressure assumption is acceptable.

secondly based on ur equations there is no constant volume assumtion!! those are constant pressure assumption equations.

Regards

Timaji

 All times are GMT -4. The time now is 14:06.