Learning Forum

[AMR96]

Hello,

I am doing a project on CFD simulation of a PEM fuel cell. The main goal of the project is to simulate and verify the results of the fuel cell with what is already present in literature.

The model that I am currently simulating runs in the transient mode and I get fairly good residual curves after simulating the model for 10 time steps with a step size of 1e-09 and 30 iterations per time step. The problem that I am having is that after the simulation is done, the contours of the hydrogen mass fraction on the anode side show a constant value. In reality the hydrogen mass fraction has to decrease as we approach the anode outlet. Additionally, the min_h2 and mean_h2 are the exact same value as the simulation progresses which doesn't seem correct.

I have no idea where the problem is. I have double-checked my inputs with what is in the literature and there is very little difference however I still don't know why the hydrogen mass fraction doesn't change.

I would like to know if anyone has encountered such problem or know what is causing this issue?

Any is help is very much appreciated.

[KR]

Hello:
Do you see the decrease at such low time scales (1e-9 to 1e-8 s)? Or do you need to run the simulation a little longer to see some decrease? The time scale of the problem might be something to think about here.
Karthik