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Question about "net reaction rate of species n" in results with EDC model

Hi everyone,

I've been post-processing the numerical results with EDC model recently. I compared the results exported directly from Fluent. The kinetic rate of reaction-n is in the same order of magnitude, but why the net reaction rate in the results EDC is several orders of magnitude smaller than the results with finite-rate?

Hope someone can offer some thoughts about this question.

Hi

I have no exprience with EDC, but I can tell you what I know about the EDM/Finite-rate model.

Quote:

In the latter, Fluent calculates two reaction rates: 1) the EDM one associated with turbulent eddies and 2) the Finite rate one associated with Arrhenius chemistry.
During the post-processing you'll see that 2 rates appear for each reaction + the net one. In this model (EDM/Finite-rate), the net rate is simply taken as the minimum of the two. This is done to prevent ignition in zones of low turbulence (before flame holders). After ignited, the eddy dissipation rate is generally smaller than the kinetic rate, and will appear as the net reaction rate.

So depending on your system and flow characterstics, the net rate will be either the eddy dissipation one or kinetic with most likely the eddy dissipation rate being the net rate because these models are mixing-controlled.

Perhaps someone with experience on the EDC model can jump in and give you a better description

Quote:

Originally Posted by alainislas (Post 838393)

Hi

I have no exprience with EDC, but I can tell you what I know about the EDM/Finite-rate model.

Perhaps someone with experience on the EDC model can jump in and give you a better description

Hi, Alain!

Thanks for sharing your knowledge. I will take a deep look at the Net-reaction-rate calculated in Eddy dissipation model.