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Combustion model for turbulent flow

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Old   February 8, 2006, 12:34
Default Combustion model for turbulent flow
  #1
James Willie
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Hi Everyone,

I am doing simulation for gas turbine burner. The Damkohler no.is less than one and so chemistry is slow and the chemical time scale is less than the turbulent time scale. Has anyone been able to make the Finite rate chemistry model in fluent run for a turbulent reacting flow? Any suggestions on how you got it to work will be appreciated. I am simulation methane-air reaction and the flow is compressible and boundary conditions are velocity inlet and pressure outlet.

Thanks.

James

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Old   February 8, 2006, 15:00
Default Re: Combustion model for turbulent flow
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balmiki
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hi i think , since u r simulating gas turbine burner where the flow is highly turbulent and combustion is non-premixed , my suggestion is, u should try non-premixed combustion model with PDF table.

OR use species transport model with volumetric reaction and eddy-dissipation model for turbulance chemistry intraction.
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Old   February 9, 2006, 04:40
Default Re: Combustion model for turbulent flow
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James Willie
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Hi,

Thanks for the help. At the moment, my mixture is pre-mixed and lean. Also, I am able to have solution using the finite rate/eddy dissipation model as you rightly suggested. But this model is not able to account very well for chemistry. Because my flow is also compressible, i am not able to use the PDF model. This model only works for incompressible flows, like the TFC (Turbulent flame closure) model. The only option i have now is the finite rate chemistry model which seems not to work for turbulent flows with combustion. I have the impression that this model exaggerates the turbulent flame speed and so also due to the temperature sensitivity of the rate of reaction, turning the pre-exponential factor and the activation energy is very difficult.

May be someone out there was able to have this model work for a gas turbine burner simulation.

Anyway, thanks for your suggestions and do have a good day.

James

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Old   February 12, 2006, 14:33
Default Re: Combustion model for turbulent flow
  #4
cg
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For Da<1, you can use the Laminar chemistry model; enable the Stiff Chemistry button.
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