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b eqn in XiFOAM

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Old   May 21, 2011, 04:19
Default b eqn in XiFOAM
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Farshad
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Hi,

I have used ignition in XiFoam, but the b variable never changes from 1 inside my domain which is a premixed burner.

I have this problem in both RANS and LES simulation.

Kind Regards,

Farshad
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Old   May 22, 2011, 11:10
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Hi,
this means that no combustion has occured. Could you provide us with some more details. What are ur boundary conditions? Log file..

Peter
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Old   May 24, 2011, 01:20
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Farshad
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Dear Peter,

I have attached my boundary conditions. The case is a premixed burner with a simple flameholder. The outlet is atmosphere.
please tell me why ignition does not occur.

Kind Regards,

Farshad
Attached Files
File Type: gz farshadinstabilitLESuniversity.tar.gz (3.8 KB, 19 views)
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Old   May 24, 2011, 06:38
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Does the solver find the ignition cells? Is it explicitly written on the screen?
Maybe change the postion of the ignited cells.
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Old   May 24, 2011, 10:16
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Hi,

Thanks. Is it true that ignition cell location should be in meters?
I changed the position very much but it nothing happened.
Am i correct about other options in ignition sites?
Did you look at my case? Is it ok about igintion sites?

Thanks
Farshad
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Old   May 24, 2011, 10:41
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Hi
Could you please post the output of the beginning of ur simulation? Or logfile? I ve no experiences with burners, because I am using the premixed combustion model for internal combustion engines. Thus I don t know if ur bc are right. But I will face that problem also very soon. Have you tried to use the values given by the tutorials in the XiFoam folder?

Peter
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Old   May 28, 2011, 13:36
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Farshad
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Dear Peter,

I do not receive any error in my simulation and i used the same boundary condition for LES of XiFOAM for 2D case given in the tutorial.
My problem is that only my b variable doesnt change from 1.

Thanks
Farshad
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