how to add additional species diffusion term in FLUENT

Sowmiya · February 21, 2021, 18:23

Hi all,
I want to include additional species diffusion term through UDF in FLUENT as in formula below.
The first term on the right can be included in mass diffusivity using DEFINE_DIFFUSIVITY macro in species transport model having unit to be (m^2/s) but the next term have unit to be (kg/m.s) how and where to include it?
please kindly help me with your suggestions.
diffusion term.png

I have considered four species in my simulation.

Thanks in advance

Sowmiya · February 22, 2021, 16:37

Please experts give me few suggestions to carry out my work

Sowmiya · February 27, 2021, 07:12

The above query is how to add the highlighted part of the equation (shown below) in FLUENT.

Achini · March 28, 2021, 14:34

Hello Sowmiya,

Were you able to find a solution to your problem?

I have the same problem with my simulation and I am planning to add the secondary diffusion term using a UDF.

February 21, 2021, 18:23	how to add additional species diffusion term in FLUENT	#1
Sowmiya New Member Tamil Nadu Join Date: Dec 2019 Posts: 11 Rep Power: 7	Hi all, I want to include additional species diffusion term through UDF in FLUENT as in formula below. The first term on the right can be included in mass diffusivity using DEFINE_DIFFUSIVITY macro in species transport model having unit to be (m^2/s) but the next term have unit to be (kg/m.s) how and where to include it? please kindly help me with your suggestions. diffusion term.png I have considered four species in my simulation. Thanks in advance Last edited by Sowmiya; February 22, 2021 at 16:36.

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February 22, 2021, 16:37		#2
Sowmiya New Member Tamil Nadu Join Date: Dec 2019 Posts: 11 Rep Power: 7	Please experts give me few suggestions to carry out my work

March 28, 2021, 14:34		#4
Achini Member L.A.Isanka Join Date: Jul 2020 Posts: 55 Rep Power: 6	Hello Sowmiya, Were you able to find a solution to your problem? I have the same problem with my simulation and I am planning to add the secondary diffusion term using a UDF.