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Deffusion Coeff.

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Old   March 26, 2003, 20:35
Default Deffusion Coeff.
  #1
yeewan
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Hi everyone, Now i have a case where a gas will diffuse into a porous media. But before that, the diffusing gas will pass through a inlet pipe which donnot contain the porous media.

I am using the species transport model. So my question is, what diffusio coeffient should i use?? the diffusion coeff for gas-gas? or the Deff for the gas-solid?? Thanks,
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Old   April 14, 2003, 08:57
Default Re: Deffusion Coeff.
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Steven
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Hello,

In this case, you may want to use different diffusion coefficients for different regions.

Dg0:diffusivity of the gas

Dg,eff:effective diffusivity of the gas in porous region

Dg,eff=Dg0*(porosity)^(turtuosity)

I hope that answered your question.

Steven
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Old   April 14, 2003, 20:55
Default Re: Deffusion Coeff.
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yeewan
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Thanks steven.
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Old   April 15, 2003, 04:29
Default Re: Deffusion Coeff.
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yee wn
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The Do and Deff i knew already. but then stev, in fluent i think we only can input one D for one gas pair... am i right?? correct me if i am wrong. So how do i input two different D??

anythings helpfull will be appreciated. what do you thinks, stev.??

also, can anyone provide some references about gas-gas diffusion in porous media so that i can verify my simulation.

THANKS TYW
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