fireFOAM convergence

Cristiano · July 9, 2010, 10:47

Hello everyone,

I have run my simulation 1 week ago. I do not understand the reason for which it takes me a long time.
My grid counts around 12000 cells and I think I have set the parameters in controlDict file properly.

Any advice?

Cristiano

marcbest · July 9, 2010, 11:14

hi christiano,

i think it depends - amongst others - on your computer (clock rate and RAM), the deltaT and endTime in your controlDict and the number of species...

i hope this helps, otherwise you should describe your problem more detailled...

regards and have a nice weekend

Cristiano · July 9, 2010, 11:55

I have run my case (Jet in Hot Coflow) in parallel on two processors. I have got a non confined jet with three different inlets:
air (N2, O2);
hot combustion products (N2, O2, CO2, H2O);
fuel (CH4).

I have checked each parameters in controlDict file and everything should be OK.

deltaT=0.0001 (based on the Courant number)
maxCo=0.1
maxDeltaT=0.001

What piece of information do you need to understand my problem?

Thank You again.

Cristiano

marcbest · July 9, 2010, 12:35

so i don't really know, are the residuals still too high? perhaps somthing is wrong in the case and the residuals are oscillating...
has someone else an idea?

Cristiano · July 9, 2010, 12:47

I have noticed physical time are not changing during the run. It has been the same for days.
I can read deltaT = 1e-17. For this reason, I should have really high velocity in some point of the domain.

???

babakflame · May 22, 2013, 08:21

Dear Buddies
Hi
I want to use fireFoam for simulating DLR flame (Fuel: CH4-H2-N2 and Oxidizer: air); I think I have set my case in proper state; However, After running my case it seems that the jets are still in cold situation and the combustion did not started

; Would some body please hint me what is the problem? I can upload the necessary files i.e. combustion, chemistry, reaction or anythng else

Regards
Bobi

July 9, 2010, 10:47	fireFOAM convergence	#1
Cristiano New Member Cristiano Join Date: Jun 2010 Posts: 14 Rep Power: 16	Hello everyone, I have run my simulation 1 week ago. I do not understand the reason for which it takes me a long time. My grid counts around 12000 cells and I think I have set the parameters in controlDict file properly. Any advice? Cristiano

July 9, 2010, 11:55	fireFoam convergence	#3
Cristiano New Member Cristiano Join Date: Jun 2010 Posts: 14 Rep Power: 16	I have run my case (Jet in Hot Coflow) in parallel on two processors. I have got a non confined jet with three different inlets: air (N2, O2); hot combustion products (N2, O2, CO2, H2O); fuel (CH4). I have checked each parameters in controlDict file and everything should be OK. deltaT=0.0001 (based on the Courant number) maxCo=0.1 maxDeltaT=0.001 What piece of information do you need to understand my problem? Thank You again. Cristiano

July 9, 2010, 12:47	fireFoam convergence	#5
Cristiano New Member Cristiano Join Date: Jun 2010 Posts: 14 Rep Power: 16	I have noticed physical time are not changing during the run. It has been the same for days. I can read deltaT = 1e-17. For this reason, I should have really high velocity in some point of the domain. ???

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July 9, 2010, 11:14		#2
marcbest New Member Join Date: May 2010 Location: Cologne Posts: 27 Rep Power: 16	hi christiano, i think it depends - amongst others - on your computer (clock rate and RAM), the deltaT and endTime in your controlDict and the number of species... i hope this helps, otherwise you should describe your problem more detailled... regards and have a nice weekend

July 9, 2010, 12:35		#4
marcbest New Member Join Date: May 2010 Location: Cologne Posts: 27 Rep Power: 16	so i don't really know, are the residuals still too high? perhaps somthing is wrong in the case and the residuals are oscillating... has someone else an idea?

May 22, 2013, 08:21		#6
babakflame Senior Member Bobby Join Date: Oct 2012 Location: Michigan Posts: 454 Rep Power: 16	Dear Buddies Hi I want to use fireFoam for simulating DLR flame (Fuel: CH4-H2-N2 and Oxidizer: air); I think I have set my case in proper state; However, After running my case it seems that the jets are still in cold situation and the combustion did not started ; Would some body please hint me what is the problem? I can upload the necessary files i.e. combustion, chemistry, reaction or anythng else Regards Bobi