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-   -   Single flamelet extinguished error from chemical reaction problem (http://www.cfd-online.com/Forums/fluent/98681-single-flamelet-extinguished-error-chemical-reaction-problem.html)

Jenny_Wong March 16, 2012 04:50

Single flamelet extinguished error from chemical reaction problem
 
Hi Everyone,
I'm trying to set up a chemical reaction case in FLUENT. It is a single step irreversible reaction of HCl and NaOH (both are liquid). I have created CHEMKIN Mechanism file and Thermodynamic Database file. The reaction data I wrote is:

ELEMENTS
H O NA CL
END
SPECIES
NACL NAOH HCL H2O
END
REACTIONS
NAOH + HCL => NACL + H2O 2.81E-10 0.0 0.0
END

I use non-premixed combustion and steady flamelet model. I am able to load both reaction and thermodynamic files but when I click create flamelet option, FLUENT reports this error:
"Single flamelet extinguished. Try again with lower Scalar Dissipation"

I try reducing the initial scalar dissipation to a very lower number but still, it does not work.

I do not know what is wrong. Can anyone give me some advice/suggestion on how to solve this problem, please? Thank you very much.

Regards,
Jenny

cguy March 17, 2012 06:36

The flamelet solver in Fluent checks for heat release to ensure that the flamelet has not extinguished (ie the max temp > boundary temp). Can you give your chemistry some exo-thermistry? (ie lower formation enthalpy of products)

Jenny_Wong March 17, 2012 08:01

Dear Cguy,
Thank you very much for your reply. I don't know how to give my chemistry exo-thermistry or lower product formation enthalpy. Could you please give me some ideas?
Best wishes,
Jenny


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