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Reduceing activation energy in methane-air combustion

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Old   January 27, 2013, 04:15
Default Reduceing activation energy in methane-air combustion
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Knight Huang
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Hey Guys,

I am trying to ignite a methane-air combustion in a 3-D burner with complex geometry. I patch the 2000K and 0.01 specice for the combustion chamber, but it can't be ignited. Thus, I reduce the activation energy of methane-air in the Finite-Rate model, it was easy to ignite. Could you tell me is that correct? What is difference between the present result and the results with previous default value?

Beside, there are many small gas-holes in the burner, I am trying to simulate the flashback from the holes into the burner. Can I assume the multi-holes zone as the porous media? Do you guys have any idea about simulate the flashback from these small gas holes?

I really appeciate if anyone can give me some points about above. Thanks a lot!

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Old   January 27, 2013, 05:19
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There should be a samll amout of both reactants, oxidants and products and also high temperature to could be ignited.
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Old   January 27, 2013, 05:51
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Quote:
Originally Posted by msaeedsadeghi View Post
There should be a samll amout of both reactants, oxidants and products and also high temperature to could be ignited.
Hi Saeed,

I have patched the temperture T=2000k in combustion chamber, but it was still not ignited. So do you think I can use higher temperture like 3000k? Thank you very much.

Knight
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Old   January 27, 2013, 07:27
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2000K is enough. You should change other parameters ot could ignite it. By the way you can also use spark ignition instead of patching high temperature.
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Old   January 27, 2013, 07:36
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Quote:
Originally Posted by msaeedsadeghi View Post
2000K is enough. You should change other parameters ot could ignite it. By the way you can also use spark ignition instead of patching high temperature.
Hey Saeed,

Could you tell me what kind of the parameters should I change? Thanks.

Actually, we did the experimental test using the hot surface ignition and pilot ignition, so I think if i take the spark ignition that may be inappropriate? Thanks a lot. Hope you get more response from you. Reallly appeciate for that.

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Knight
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Old   January 27, 2013, 07:43
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spark ignition is OK. You can simulate experimental spark using it. I should see your case to could help.
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Old   January 27, 2013, 07:52
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Originally Posted by msaeedsadeghi View Post
spark ignition is OK. You can simulate experimental spark using it. I should see your case to could help.
Hey Saeed,

Could you show me what kind of the other parameters I can change? Thanks.

We didn't use the spark for ignition in our experiemnt, so I think it may not be good for the simulation. Can you pass me your email address then I will pass me my case to you. Thanks

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Knight
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Old   January 27, 2013, 07:56
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You could find my email using my signature link.
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Old   January 27, 2013, 08:06
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You could find my email using my signature link.
Soorry, I can't open it.
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Old   January 27, 2013, 08:07
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Please zip then send.
saeed@me.iut.ac.ir
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Old   January 28, 2013, 13:05
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Be sure to include both reactants and products initially in your fluid.
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