2.8 Fuel Cell and Electrolysis Model Boundary Conditions

The following boundary conditions need to be defined for the Fuel Cell and Electrolysis simulation based on your problem specification:

• Anode Inlet
  • Mass flow rate

  • Temperature

  • Direction specification method

  • Mass fractions (e.g., h2, and h2o).

  • The coolant must be set to zero if coolant channels are enabled.

  • UDS-2 (Water Saturation) must be set to 0

• Cathode Inlet
  • Mass flow rate

  • Temperature

  • Direction specification method

  • Mass fractions (e.g. o2, h2o, and n2).

  • The coolant must be set to zero if coolant channels are enabled.

  • UDS-2 (Water Saturation) must be set to 0

• Coolant Inlet (if any)
  • Mass flow rate

  • Temperature

  • Direction specification method

  • Coolant mass fraction set to 1

  • UDS-2 (Water Saturation) must be set to 0

• Pressure Outlets (all)

  Realistic backflow conditions.

• Terminal Anode
  • Temperature (or flux if known)

  • UDS-0 (electric potential) set to ground voltage

• Terminal Cathode
  • Temperature (or flux if known)

  • UDS-0 (electric potential) is set to the voltage of the cathode (if solving to constant voltage), or the UDS-0 (electric potential) flux is set to the current density in A/m $^2$(SI units) (if solving for constant current). Note that the sign of the UDS-0 flux on the cathode side is negative.