define mass diffusivity for each zone

February 3, 2009, 11:22

Dear Fluent-User!

I am modelling mass transfer in two zones.

One zone is a normal duct and another zone is a porous media.

I want to use kinetic theory for mass diffusivity in the duct.

For the porous media, as I know, I must write DEFINE_DIFFUSIVITY.

But, if I define DEFINE_DIFFUSIVITY in the materials panel, I can not use kinetic theory, can I?

What can I do for this case?

Thank you in advance

natantyt · October 17, 2011, 21:36

Hi Kim

I have a similar problem, did you find any answer? it would help me a lot. I want to use the kinetic option theory for both and then use C_DIFF_L macro to manipulate the diffusivity. What do you suggest? I had a problem with my UDF.h code it is online now.

Cheers,

February 3, 2009, 11:22	define mass diffusivity for each zone	#1
kim Guest Posts: n/a	Dear Fluent-User! I am modelling mass transfer in two zones. One zone is a normal duct and another zone is a porous media. I want to use kinetic theory for mass diffusivity in the duct. For the porous media, as I know, I must write DEFINE_DIFFUSIVITY. But, if I define DEFINE_DIFFUSIVITY in the materials panel, I can not use kinetic theory, can I? What can I do for this case? Thank you in advance

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October 17, 2011, 21:36		#2
natantyt Member Nathan Join Date: Aug 2010 Posts: 62 Rep Power: 16	Hi Kim I have a similar problem, did you find any answer? it would help me a lot. I want to use the kinetic option theory for both and then use C_DIFF_L macro to manipulate the diffusivity. What do you suggest? I had a problem with my UDF.h code it is online now. Cheers,