Species balance

Bruno Machado · January 12, 2016, 11:31

Hello everyone,

I am working with a a fuel cell and I modeled it using UDF. My mixture has H2, O2, H2O and N2.

On one side, the anode, I am feeding H2+H2O and I have the consumption of H2 and production of H2O due to reaction (no O2 or N2 is feeded). On the other side, cathode, I am feeding it with O2, H2O and N2 and I have the consumption of O2 and H2O, tho N2 does not play any role at all. All the source terms for H2, O2 and H2O are correct and the sum of them is deducted from the continuity equation.

The membrane at the center of the fuel cell is a solid domain, so it is impenetrable by any of the species. The problem I am facing is that N2 is found on the anode side, while it was not supposed to find any N2 on anode. From fluent manual, fluent solves (n-1) equations and the "n" equation is 1 - the sum of other species, so I have not found any way to keep 2 species (O2 and N2) as 0 on the anode side.

Any suggestions of how to solve this problem?

Thank you.

mahbod · September 8, 2017, 03:57

I faced to the same problem!!!
Is there any solution?
Do you find the reason??

January 12, 2016, 11:31	Species balance	#1
Bruno Machado Senior Member Bruno Machado Join Date: May 2014 Posts: 271 Rep Power: 13	Hello everyone, I am working with a a fuel cell and I modeled it using UDF. My mixture has H2, O2, H2O and N2. On one side, the anode, I am feeding H2+H2O and I have the consumption of H2 and production of H2O due to reaction (no O2 or N2 is feeded). On the other side, cathode, I am feeding it with O2, H2O and N2 and I have the consumption of O2 and H2O, tho N2 does not play any role at all. All the source terms for H2, O2 and H2O are correct and the sum of them is deducted from the continuity equation. The membrane at the center of the fuel cell is a solid domain, so it is impenetrable by any of the species. The problem I am facing is that N2 is found on the anode side, while it was not supposed to find any N2 on anode. From fluent manual, fluent solves (n-1) equations and the "n" equation is 1 - the sum of other species, so I have not found any way to keep 2 species (O2 and N2) as 0 on the anode side. Any suggestions of how to solve this problem? Thank you.

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September 8, 2017, 03:57		#2
mahbod New Member Mahbod Moein-Jahromi Join Date: Jan 2017 Posts: 2 Rep Power: 0	I faced to the same problem!!! Is there any solution? Do you find the reason??