Hello, For the species conservation equation contained in YEqn.H there is an mvConvection scheme listed. I am trying to understand how the diffusion works in reactingFOAM and it seems, to me, that this is the only term I do not understand in the conservation equation. Can any reacting folks help me decipher what is going on here? I'd like to add a more detailed diffusion to reactingFoam, so I think this falls under the extend project
thanks,
Ryan

YEqn.H file:
tmp<fv::convectionScheme<scalar> > mvConvection
(
fv::convectionScheme<scalar>::New
(
mesh,
fields,
phi,
mesh.divScheme("div(phi,Yi_h)")
)
);

{
label inertIndex = -1;
volScalarField Yt = 0.0*Y[0];

for (label i=0; i<Y.size(); i++)
{
if (Y[i].name() != inertSpecie)
{
volScalarField& Yi = Y[i];

solve
(
fvm::ddt(rho, Yi)
+ mvConvection->fvmDiv(phi, Yi)
- fvm::laplacian(turbulence->muEff(), Yi)
==
kappa*chemistry.RR(i),
mesh.solver("Yi")
);

Yi.max(0.0);
Yt += Yi;
}
else
{
inertIndex = i;
}
}

Y[inertIndex] = scalar(1) - Yt;
Y[inertIndex].max(0.0);
}
~

Hi,

As far as I know this myConvection is scheme for advection (or convection) processses not for diffusion. Since reactingFoam is the turbulent solver diffusion is only from turbulence and is here: turbulence->muEff(). You have to go deeper into turbulence class.

Regards,
Kamil

Thanks Kamil, definitely getting in deep with doxygen here, hopefully we can create a better diffusion model for laminar simulaitons.

thanks,
Ryan

Hi Ryan,

I have developed a library (1.6-ext and 1.7) that can better simulate the laminar diffusion in reactingFoam. I can share the library, the solver and the test case.

In README.txt (lib subfolder) you can find the detailed description of what the code does. in .pdf file you can find the theoretical description.

The code is "young" and probably one can optimize the coding and some theoretical aspects. I have sent it to Hrvoje Jasak in order to include it (or a part of it) in the main release, but I suppose that this work is not good enough and it has to be improved.

To install the library copy the lib subfolder inside $FOAM_USER/lib. Application and run subfolder can be placed everywhere.

I hope that this code can be useful. If you find it interesting please give me a feedback. Like reported in .pdf file many people have worked on it. I am the main "coder", but other people have played a fundamental role in the theoretical background. This work is really a team work! Please cite all people present in .pdf file in case you can utilize the library for your purposes.

Regards

Valerio

P.S.

I can't attach the two files. Send me an e-mail (valerio.novaresio@polito.it) to obtain them.

Valerio,
Thanks for the post! This looks great and I am excited to receive your code. I am going to go ahead and creat a new forum feed in the case that any other people in the community is looking use laminar diffusion in reactingFoam.

thanks again Valerio, I look forward to receiving the code via email.

best,
Ryan

Hi,

First of all, thank you Ryan for starting this thread. I'm looking at accounting for more detailed diffusion in reactingFoam too.

Good day, Valerio. I'm interested in integrating the library developed by you and your team. Is it possible that you share the code? I'm pleased to contact you via email, if you don't mind. I look forward to hearing from you. Many thanks in advance.

Best regards,
Karmun.