b eqn in XiFOAM

Farshad_Noravesh · May 21, 2011, 05:19

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, 12:10

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, 02:20

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, 07:38

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, 11:16

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, 11:41

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, 14:36

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

May 21, 2011, 05:19	b eqn in XiFOAM	#1
Farshad_Noravesh Member Farshad Join Date: Oct 2010 Posts: 76 Rep Power: 16	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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May 22, 2011, 12:10		#2
Peter_600 Senior Member Join Date: Oct 2009 Posts: 140 Rep Power: 17	Hi, this means that no combustion has occured. Could you provide us with some more details. What are ur boundary conditions? Log file.. Peter

May 24, 2011, 07:38		#4
Peter_600 Senior Member Join Date: Oct 2009 Posts: 140 Rep Power: 17	Does the solver find the ignition cells? Is it explicitly written on the screen? Maybe change the postion of the ignited cells.

May 24, 2011, 11:16		#5
Farshad_Noravesh Member Farshad Join Date: Oct 2010 Posts: 76 Rep Power: 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

May 24, 2011, 11:41		#6
Peter_600 Senior Member Join Date: Oct 2009 Posts: 140 Rep Power: 17	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

May 28, 2011, 14:36		#7
Farshad_Noravesh Member Farshad Join Date: Oct 2010 Posts: 76 Rep Power: 16	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