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Old   February 16, 2004, 11:30
Default Energy balance
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I'm simulating gas combustion in a rotary kiln using the two-step eddy dissipation model. When I report/flux/total energy, to do an energy balance I get strange values.

My inlet values are negative and my outlet are positive. Also, I'm getting a much higher outlet value than I'm putting in.

I know this isn't a lot of information but can anyone tell me what I'm doing wrong? I'm following the tutorial 'Using the Non-Premixed Combustion Model'. I know this is has two phase combustion but I think the method is the same, may be I'm wrong??


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Old   February 17, 2004, 20:33
Default Re: Energy balance
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Fluent reports the total enthalpy (chemical, which is -ve, plus thermal, which is +ve). So, it is possible to have -ve enthalpy going in and +ve enthalpy coming out. Since enthalpy is relative, this should not matter. However, energy must balance - make sure that your energy and species URFs are 1, or nearly 1.
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