Laminar Burning Velocity Calculations with Fluent

nasehandarzgoo · January 24, 2014, 10:26

I am trying to run a simple case of premixed laminar methane-air flame.
In order to investigate effects of acoustic waves on it, but not for now.

I heard that you can easily get wrong laminar flame speed in Fluent if your grid is not fine enough and if you use default values of single step chemistry.
So I was introduced to make a quasi 1D model (on element in height and thousands in length) ans apply the mixture as velocity inlet and check the flame speed.

I can run this simulation and the flame forms in a distance.
Now how can I actually calculate the laminar burning velocity?
I was told I can use this formula:

S_Laminar = (1/rho_unburnt)*Integral{(rho*dY/dt)dx

Would you please tell me how I can extract these parameters in Fluent?

Thank you.

adithyakc02 · May 12, 2017, 06:53

Hi, I am also trying to find the laminar burning velocity for Heat Flux Burner for premixed methane air flame using drm19 mechanism. If you have found how to extract the data to find laminar burning velocity, can you please let me know?

Kind regards,
Adithya

nasehandarzgoo · May 12, 2017, 07:25

Dear Adithya,

You need to run your simulations in the quasi 1D domain I have mentioned in the original post, and then run it in transient mode and export the temperature profile or reaction heat profile for every few time steps.

Then in Excel (or similar) you can calculate the flame movement speed.
Depending on your inlet velocity you can then calculate it simply by a relative velocity concept

January 24, 2014, 10:26	Laminar Burning Velocity Calculations with Fluent	#1
nasehandarzgoo New Member Naseh Hosseini Join Date: Jul 2012 Posts: 6 Rep Power: 14	I am trying to run a simple case of premixed laminar methane-air flame. In order to investigate effects of acoustic waves on it, but not for now. I heard that you can easily get wrong laminar flame speed in Fluent if your grid is not fine enough and if you use default values of single step chemistry. So I was introduced to make a quasi 1D model (on element in height and thousands in length) ans apply the mixture as velocity inlet and check the flame speed. I can run this simulation and the flame forms in a distance. Now how can I actually calculate the laminar burning velocity? I was told I can use this formula: S_Laminar = (1/rho_unburnt)Integral{(rhodY/dt)dx Would you please tell me how I can extract these parameters in Fluent? Thank you.

May 12, 2017, 06:53	Laminar burning velocity	#2
adithyakc02 New Member Join Date: May 2017 Posts: 1 Rep Power: 0	Hi, I am also trying to find the laminar burning velocity for Heat Flux Burner for premixed methane air flame using drm19 mechanism. If you have found how to extract the data to find laminar burning velocity, can you please let me know? Kind regards, Adithya

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May 12, 2017, 07:25		#3
nasehandarzgoo New Member Naseh Hosseini Join Date: Jul 2012 Posts: 6 Rep Power: 14	Dear Adithya, You need to run your simulations in the quasi 1D domain I have mentioned in the original post, and then run it in transient mode and export the temperature profile or reaction heat profile for every few time steps. Then in Excel (or similar) you can calculate the flame movement speed. Depending on your inlet velocity you can then calculate it simply by a relative velocity concept