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Old   February 9, 2007, 10:16
Default eddy break-up artificial flames
  #1
Hugo
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Hello Users,

I'm using Fluet to model wood combustion, with the eddy dissipation model for gaseous combustion HOWEVER I get flames in all the wrong places - at the edges of bluff bodies, not above the wood pile. the CFD Wiki (http://www.cfd-online.com/Wiki/Combustion) says that this is a known problem for eddy break-up models and some packeges have a way round it... but gives no details! Can anyone advise?

Thanks, Hugh.
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Old   February 9, 2007, 16:53
Default Re: eddy break-up artificial flames
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Dmitriy
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Hi Hugh,

Just a suggestion (one of many possible reasons, not necessarily correct in your particular case): is your combustion regime is "well ventilated"? i.e. is it enough oxygen around your wood pile for flame to appear there? I think I saw simulations of diffusion combustion with EBU model (but different from FLUENT CFD code) showing flame not at the fuel source (in a room), but where oxygen is available (behind window openings).

Regards,

Dmitriy

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Old   February 12, 2007, 05:51
Default Re: eddy break-up artificial flames
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Hugo
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Hi Dmitriy,

Yes, it is well ventilated - air coming up thorugh a bed of wood, which is devolatilising. There is a small flame at teh edge of the first piece of wood, then far far away at the trailing edge of a lip at the outlet, but not directly above teh wood as you would expect.

Still confused! Hugo.
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Old   February 12, 2007, 08:19
Default Re: eddy break-up artificial flames
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Dmitriy
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Hugo, Sorry then - no clue. Dmitriy
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