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Pyrolisis energy equation

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Old   May 22, 2014, 17:25
Default Pyrolisis energy equation
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Hello All!

I have a rather simple (for experienced users) question regarding the pyrolysis (reactingOneDim model) energy equation.
The energy equation which is calculating T in pyrolysis zone takes the form:

fvm::ddt(rhoCp, T_)
- fvm::laplacian(K_, T_)
+ fvc::div(phiQr)
+ fvc::div(phiGas)

I understand that the on the left-hand said of the equation we have the enthalpy(advection) [fvm::ddt(rhoCp, T_)] + convection [fvm::laplacian(K_, T_)]. This part is rather simple. On the right hand side we however have :

1.fvc::div(phiQr) which I assume to be a radiation part but If I try to follow the phiQr in a code I only find const surfaceScalarField phiQr(fvc::interpolate(Qr_)*nMagSf()); which tells me nothing - I would rather expect something in a form of Stefan-Boltzman law with T^4... Where can I find it?

2.chemistrySh_ - tells me nothing - tracing in in code give me the "dead end" at chemistrySh_ = solidChemistry_->Sh()(); how does it work? What is the physical sense?

fvc::div(phiGas) - also I dont understand this - we have the divergence of something which I cannot trace down in a code - it also looks like something connected with the advection but I might be wrong - and certainly two advective parts have no sense to me.On the top of this I have considered the energy equation in pyrolysis process as an non-linear task. Since the temperature at the pyrolysis zone is dependent on a amount of heat radiated out, which in turn is dependent on temperature at the pyrolysis zone. Here we come to the iterative cycle which I cannot find in the code.

I would be grateful If you can give me any help in understanding the model.
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