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-   -   b eqn in XiFOAM (http://www.cfd-online.com/Forums/openfoam/88595-b-eqn-xifoam.html)

Farshad_Noravesh May 21, 2011 04:19

b eqn in XiFOAM
 
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

Peter_600 May 22, 2011 11:10

Hi,
this means that no combustion has occured. Could you provide us with some more details. What are ur boundary conditions? Log file..

Peter

Farshad_Noravesh May 24, 2011 01:20

case
 
1 Attachment(s)
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

Peter_600 May 24, 2011 06:38

Does the solver find the ignition cells? Is it explicitly written on the screen?
Maybe change the postion of the ignited cells.

Farshad_Noravesh May 24, 2011 10:16

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

Peter_600 May 24, 2011 10:41

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

Farshad_Noravesh May 28, 2011 13:36

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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