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AML:FC–FLUENT Hybrid Modelling Interface

The ultimate tool for detailed predictive fuel cell stack modelling

CFD model of flow channel cells

gPROMS-CFD link architecture

gPROMS model of membrance-electrode assembly (MEA)

The AML:FC-FLUENT Hybrid Modelling Interface (HMI) for detailed cell stack modelling is used to combine the power of gPROMS for modelling of the membrane assembly with the power of ANSYS's FLUENT® for modelling flow channel fluid dynamics.

Application

The AML:FC–FLUENT HMI is used for modelling situations where:

  • it is necessary to model the membrane electrode assembly (MEA) to a high level of fidelity, taking into account all related mass and heat transfer, reaction and electrochemistry phenomena (as is usually the case)
  • at the same time it is necessary to take into account phenomena best modelled by CFD packages, such as:
    • fuel or air flow through complex geometry – for example serpentine channels
    • heat radiation between cell and the external environment.

Advantages and benefits

The AML:FC HMI combines the best of gPROMS and CFD modelling:

  • by taking all relevant interactions into account simultaneously it provides extreme accuracy of modelling of all relevant phenomena in both the flow channels and the MEA
  • advanced built-in model reduction techniques enable rapid and robust solution, with complex stack design models solved in times that are orders of magnitudes faster than for the equivalent CFD-alone run.

The results can be used to determine temperatures, concentrations and other quantities at all points in the stack design with a high degree of confidence.

This enables many different aspects of stack design to be analysed and optimised based on accurate numbers.

How it works

Current density across the cell surface
Current density across a cell surface

Current density across the stack
Current density over a 100-cell stack

The interface works as shown in the diagram to the right above.

Multiple instances of the gPROMS high-fidelity 1-D MEA model are linked to corresponding cells in the air and fuel flow channels, which are modelled in FLUENT®. During solution the gPROMS model is called for each pair of adjacent FLUENT cells until the simulation is converged.

The result is a fast calculation that provides three-dimensional representation of key variables in the cell with a high degree of accuracy. The upper diagram to the right shows the current density across the anode surface for a cell with crossflow channel arrangement.

A similar approach is applied to modelling of multi-cell stacks. The lower colour plot to the right shows current density variation over a 100-cell stack.

The AML:FC HMI is typically used for 3-dimensional cell modelling. However it can be used in any configuration where a combination of gPROMS MEA and FLUENT models can add accuracy. PSE can provide advice on and assistance with configuration.

Information flow

The calculation for an individual pair of flow channel cells works as shown in the following diagram. Essentially gPROMS appears as a set of source terms to FLUENT.

architecture of gPROMS–CFD links and information flow (click to enlarge)

The FLUENT calculation supplies a vector of mass fractions, temperature and pressure to gPROMS. gPROMS in turn returns mass fluxes and convective heat fluxes to FLUENT in source-term form. The operation is transparent to users.

Supply

The AML:FC–FLUENT Hybrid Modelling Interface is supplied as a separately-priced optional AML:FC component under PSE's concurrent licensing arrangement.