Need help with PEM Fuel Cell Modeling using COMSOL

Click For Summary
The discussion focuses on modeling a Proton Exchange Membrane Fuel Cell (PEMFC) using COMSOL, incorporating transport equations for mass, heat, species, and charge. The user successfully validated their stationary model against a published reference but encountered issues with the dynamic voltage response during validation. Specifically, they expected to simulate an undershoot in voltage when transitioning from lower to higher current density, similar to experimental results. However, the expected dynamic voltage versus time curve was not achieved. The user seeks advice on how to effectively trigger the undershooting in the voltage response.
KATHRYN9801
Messages
1
Reaction score
0
I happen to be modelling PEMFC and accounted for various transport equation including mass, heat, species and charge. I was able to validate my stationary model based on a published reference. In validating its voltage dynamic response, I was expecting at a potentiometric conditions that an undershoot will be simulated similar to the experimental dynamic response of the reference study. Unfortunately, I was not able to gain the supposed end expected dynamic voltage vs. time curve. In this regard, does anyone knows how to trigger the undershooting in the volatge response when current is changed from lower to higher current density values?
 
Somewhat separate from the coffee advice of “buy whole beans, grind fresh at home daily”, I'm looking to understand the factors that contribute to purchased ground coffee losing freshness after opening (oxygen, humidity, temperature, time, other?). I'm assuming oxidation is the main factor, assuming normal room temperature and mid-range humidity. It appears (I'm having trouble finding good info on this) that a high quality modern pre-ground coffee is packaged in a way that maintains...

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 4 ·
Replies
4
Views
31K
  • · Replies 8 ·
Replies
8
Views
5K
  • · Replies 12 ·
Replies
12
Views
5K