[slan89]

I am using a Fluent module to simulate a 3D single channel PEMFC, and I believe I have got a converged solution. But when I display the h2o distribution contour of a cross section. I got some weird results.
As shown in the figures, the h2o fraction of the current collector area is not 0, however, it is solid. And the 8 corners of current collector is weird, too.
Please give me a reply if someone know why this should be. Thanks a lot!

[A CFD free user]

Originally Posted by slan89

I am using a Fluent module to simulate a 3D single channel PEMFC, and I believe I have got a converged solution. But when I display the h2o distribution contour of a cross section. I got some weird results.
As shown in the figures, the h2o fraction of the current collector area is not 0, however, it is solid. And the 8 corners of current collector is weird, too.
Please give me a reply if someone know why this should be. Thanks a lot!

Dear friend,
No problem regarding your modeling. I suppose you should uncheck the "global range" option in contours window. Try it and it will be OK.
May I use this place and ask you a question?

P.S. Do you have any experience in two dimensional (2D) simulation of PEM fuel cell using PEMFC module?

[beehuah]

Hello,

I'm currently working on 3D single cell PEMFC with add on PEMFC module in ANSYS 15. The simulation are not converging and error occured where divergence were detected in amg solver. I have made the simulation setting based on single channel tutorial but amg solver divergence were detected in temperature. When i lower the URF for energy, the divergence happen to X-momentum. When i lower the X-momentum termination restriction the temperature are having divergence back. Do anyone know what is the problem here? Is it due to the mesh generated from meshing that were not totally uniform? I have tried to generate mesh from ICEM but im not familiar with ICEM the mesh generated were not in good shape and I have the same problem with FLUENT by using mesh generated from ICEM.

Moreover, the value of I-cathode generated on 1st iteration are showing very high value before the divergence error prompt up. Why would this occur? Hope that I could get some guidance here. I'm stuck with this problem for months and I have no idea what should I do to resolve it. Thank you in advance.*

https://drive.google.com/file/d/0B04...ew?usp=sharing

P.S:I have refine the model and mesh generation were uniform but not perfect due to limitation of meshing in ANSYS.

[ovi_1211]

Same error I am getting. If you can get a solution please help.

[ramakant]

Originally Posted by ovi_1211

Same error I am getting. If you can get a solution please help.

Dear

You can change the value of Under relaxation factors(URFs):
Reduce the following under-relaxation-factors:
Pressure 0.5-0.7
Momentum 0.3
Protonic potential 0.95-0.99
Water content -0.95

This will help?
Regards
Ramakant