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Mass Imbalance in Reaction Stoichiometry in FLUENT

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Old   September 1, 2012, 19:33
Default Mass Imbalance in Reaction Stoichiometry in FLUENT
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Jenny
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Dear All
I'm simulating a simple chemical reaction HCl + NaOH ==> NaCl + H2O.

I create reaction mechanism files in CHEMKIN format and import them into FLUENT. However FLUENT shows "warning: mass imbalance in reaction-1 stoichiometry" and I am confused since the reaction is already balance.

Another problem is that along the centreline of my domain, the concentration of NaOH increases beyond the original concentration at the inlet. This is not realistic. The NaOH concentration should be lower than the concentration at the inlet because some of NaOH has been converted to the products.

I do not know what the problem is. If anyone has any idea or suggestion please kindly advise.
Thank you,
Jenny
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Old   September 16, 2012, 22:23
Red face Same problem...
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sir
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Hi Jenny..

I also got the same warning..I already check the stoichiometry; and it is balance..If you hv any idea, hope u don't mind to share...and i will struggle to find out the solution..

C u

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Old   September 17, 2012, 05:54
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Hi Sirly,
I'm sorry I still cannot find the solution to this. If I can solve the problem, I will let you know
Jenny
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Old   September 17, 2012, 11:57
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Ernesto
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Hello, i´ve had this problem sometimes in the past.

I´d recommend to check the Molecular wieghts of the species involved in the reactions, in the materials panel.
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Old   September 18, 2012, 11:01
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I'll do that. Thank you very much Ernesto.
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Old   October 28, 2013, 08:32
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Daniel Sebastiŕ Sáez
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Hello, I experienced the same problem and I couldn't initialize the domain and run the simulation. I checked the molecular weights of the species involved in the reaction and it can be initialized and it gives good convergence despite the fact that the same message appears.
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chemical mechanism, chemical reaction, chemkin, combustion, mass balance

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