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-   -   laminar diffusion flames in OpenFOAM? (http://www.cfd-online.com/Forums/openfoam/80073-laminar-diffusion-flames-openfoam.html)

adhiraj September 14, 2010 10:02

laminar diffusion flames in OpenFOAM?
 
Hi,
I am new to OpenFOAM, just finding my way around. I am interested in simulating laminar diffusion flames. Has any one done that? I seem to find some stuff related to turbulent diffusion flames, not much for laminar.
I am using version 1.6.
Thanks in advance.

smehdi609 September 15, 2010 11:06

You can use reactingFoam and turn off the turbulence model. That's a good model to start with. You can have different diffusion properties for different species but you still need to implement your own model for soot and Soret effect and stuff like that.

adhiraj September 15, 2010 12:44

Hi,
Thanks for replying. I am going to turn off the turbulence as a first approximation. But I did not see any option for different diffusivities for the species. In the file YEqn.H I have:
Quote:

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")
);
I think that means it assumes all species to have same diffusivity and that is equal to the viscosity. How do I change this?

smehdi609 September 15, 2010 19:16

yes, you are right. I thought we have multi-component diffusion in OpenFOAM. I checked the source code. It is not easy to implement this to both work for turbulent and laminar flames. The reason is that right now the turbulence model uses a pointer to the basic class of the thermodynamic model and in that basic definition you cannot see any implementation for the multi-component diffusion. You should start your own laminar flame solver and define your own thermo model.


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