Using UDF in fuel cell addon module

qwe2077 · January 27, 2015, 21:57

Hi I'm using PEM fuel cell addon module in fluent.
I'm tring to model the micro porous layer to a unit cell.
But in the fuel cell module, I can give only one porocity and one contact angle to the porous cell zone.
So I need to change boundary conditions in the porous media.
then I should use UDF macro to give boundary conditions.

so I got in to the pem_user.c file and found

DEFINE_DIFFUSIVITY(diff,c,t,j_spe)
{
return pem_diff(c,t,j_spe);
}

and in the pem.h file,
real pem_diff(cell_t c, Thread *t, int j_spe);

My questions are,

1. Is there no way to see the contents of pem_diff(c,t,j_spe) ?
2. How can I use UDF Macro in the fuel cell addon module?
3. Can you give me a advise about modeling extra layer of porous media?

walied123 · February 11, 2015, 15:17

hi, dear

to see the content of the addon code of fuel cell please follow the directories "C:\Program Files\ANSYS Inc\v145\fluent\fluent14.5.0\addons"

you can make change to the pem code and do the recompilation again.
see the attached pdf file for more datails.

qwe2077 · February 11, 2015, 23:33

Hi walied123 thanks for your reply.

yes I know Ansys provides user-accessable-functions in pem_user.c file in addons/src folder as you mentioned.

I want to see and change the contents of UDF of source terms and charge transfer conservation.

In the C-file, I couldn't find any content of them.

please help me

maverick123 · February 12, 2015, 03:55

If you want to see the equations how these source terms are calculated by default..check the fuel cell manual..it is given over there...

Quote:

Originally Posted by qwe2077

Hi walied123 thanks for your reply.

yes I know Ansys provides user-accessable-functions in pem_user.c file in addons/src folder as you mentioned.

I want to see and change the contents of UDF of source terms and charge transfer conservation.

In the C-file, I couldn't find any content of them.

please help me

qwe2077 · February 12, 2015, 04:18

Thanks again maverick.

I've checked out the fuel cell manual. It was a lot of help.

How can I see the c-code of default source terms and UDS flux, UDS diffusion?

Are they not opened to see?

There are only declare exression in C file and I can't find the C-code contents of those UDS function.

maverick123 · February 12, 2015, 04:25

I think, you can not see it as it is not available for Users. But you can modify it for sure with your code/equations.

Quote:

Originally Posted by qwe2077

Thanks again maverick.

I've checked out the fuel cell manual. It was a lot of help.

How can I see the c-code of default source terms and UDS flux, UDS diffusion?

Are they not opened to see?

There are only declare exression in C file and I can't find the C-code contents of those UDS function.

January 27, 2015, 21:57	Using UDF in fuel cell addon module	#1
qwe2077 New Member Brian Join Date: Jan 2015 Posts: 7 Rep Power: 12	Hi I'm using PEM fuel cell addon module in fluent. I'm tring to model the micro porous layer to a unit cell. But in the fuel cell module, I can give only one porocity and one contact angle to the porous cell zone. So I need to change boundary conditions in the porous media. then I should use UDF macro to give boundary conditions. so I got in to the pem_user.c file and found DEFINE_DIFFUSIVITY(diff,c,t,j_spe) { return pem_diff(c,t,j_spe); } and in the pem.h file, real pem_diff(cell_t c, Thread *t, int j_spe); My questions are, 1. Is there no way to see the contents of pem_diff(c,t,j_spe) ? 2. How can I use UDF Macro in the fuel cell addon module? 3. Can you give me a advise about modeling extra layer of porous media?

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February 11, 2015, 23:33		#3
qwe2077 New Member Brian Join Date: Jan 2015 Posts: 7 Rep Power: 12	Hi walied123 thanks for your reply. yes I know Ansys provides user-accessable-functions in pem_user.c file in addons/src folder as you mentioned. I want to see and change the contents of UDF of source terms and charge transfer conservation. In the C-file, I couldn't find any content of them. please help me

February 12, 2015, 04:18		#5
qwe2077 New Member Brian Join Date: Jan 2015 Posts: 7 Rep Power: 12	Thanks again maverick. I've checked out the fuel cell manual. It was a lot of help. How can I see the c-code of default source terms and UDS flux, UDS diffusion? Are they not opened to see? There are only declare exression in C file and I can't find the C-code contents of those UDS function.