Learning Forum

[krany3]

Which combustion model in Fluent is considered as the Flame Thickened Model?

[Rob]

Moving into Fluids. Also, where has that term come from?

[krany3]

I was going through a research paper where they simulated premixed combustion using flame thickened model. I just wonder, what's the equivalent model for it in Fluent. This was the reference paper, I was looking at - "Dynamically thickened flame LES model for premixed and non-premixed turbulent combustion"

[DrAmine]

We do not have automatically access to papers. It sounds after the one implementated  in Fluent. Please check that. 

[krany3]

Turbulent flame speed model calculates the turbulent flame speed by thickening the flame. But, I'm not sure if it's the same as the flame thickened model.

[seeta gunti]

Premixed flames have typical laminar flame thicknesses of the order of a millimeter. Since the laminar flame propagation speed is determined by species diffusion, heat conduction and chemical reaction within the flame, sufficient grid resolution inside the flame is necessary to predict the correct laminar flame velocity. In contrast, the combustor dimensions are usually much larger than the laminar flame thickness and the flame cannot be affordably resolved, even with unstructured and solution-adaptive grids. Fluent has separate flame thickened model which is available with LES model. You can find the model unser species models. Attached the picture for reference.

 

For more information, you can go through 7.1.2.6 in our theory guide.

Regards,

Seeta

[krany3]

Thank you

[krany3]

I'm trying to use RANS for combustion modeling. How can I use the thickened flame model with RANS? Is there any comparable model to the thickened flame model to use in RANS?

[DrAmine]

It is only available for unsteady, laminar or LES/DES/SAS turbulent cases. So you can use it with SAS which will behave as SST if there is no real global instability. 

[krany3]

Thanks