2.10 Postprocessing the Fuel Cell and Electrolysis Model

You can perform post-processing using standard ANSYS FLUENT quantities and by using user-defined scalars and user-defined memory allocations. By default, the ANSYS FLUENT Fuel Cell and Electrolysis Model defines several user-defined scalars and user-defined memory allocations, described in Table  2.10.1 and Table  2.10.2.

Table 2.10.1: User-Defined Scalar Allocations

UDS 0	Electric Potential (solid phase potential) (Volts)
UDS 1	Protonic Potential (membrane phase potential) (Volts)
UDS 2	Water Saturation (liquid saturation)
UDS 3	Water Content

Table 2.10.2: User-Defined Memory Allocations

UDM 0	X Current Flux Density (A/m $^2$)
UDM 1	Y Current Flux Density (A/m $^2$)
UDM 2	Z Current Flux Density (A/m $^2$)
UDM 3	Current Flux Density Magnitude (A/m $^2$)
UDM 4	Ohmic Heat Source (W/m $^3$)
UDM 5	Reaction Heat Source (W/m $^3$)
UDM 6	Overpotential (Volts)
UDM 7	Phase Change Source (kg/m $^3$-s)
UDM 8	Osmotic Drag Coefficient
UDM 9	Liquid Water Activity
UDM 10	Membrane Water Content
UDM 11	Protonic Conductivity (1/ohm-m)
UDM 12	Back Diffusion Mass Source (kg/m $^3$-s)
UDM 13	Transfer Current (A/m $^3$)
UDM 14	Osmotic Drag Source (kg/m $^3$-s)

You can obtain this list by opening the Execute On Demand dialog and pulling down the Function drop-down list.

Define $\rightarrow$ User-Defined $\rightarrow$ Execute On Demand...

and access the execute-on-demand function called list_pemfc_udf.

Alternatively, you can view the listing that appears when you first load your Fuel Cell and Electrolysis case, or you can type list_pemfc_udf in the text user interface and the listing will appear in the console window.

When you load older Fuel Cell and Electrolysis cases into ANSYS FLUENT, and you are monitoring a UDS using volume or surface monitors, make sure you re-visit the corresponding monitors dialog (e.g., the Volume Monitor or the Surface Monitor dialog) to make sure that the correct UDS name is used for the appropriate monitor.