PASTA²

Fuel cell systems are considered a key technology for reducing pollutant and CO₂ emissions in the mobility sector, from commercial vehicles to aviation. For efficient and long-lasting operation, both the anode-side recirculation of unused hydrogen and the cathode-side air supply must function reliably under variable operating conditions. In particular, the separation of water droplets from the anode circuit, the control of humidity, and the provision of suitable gas compositions place high demands on test methods and components. Current research projects at the TFD are predominantly at low TRLs, while industry-related developments require higher degrees of maturity.

Therefore, an infrastructure is needed that enables the validation of new technologies in the TRL 4–7 range.The PastA² project is developing a test bench for the aerodynamic, structural, and thermodynamic analysis of cathode and anode charging systems for fuel cell systems. Real multiphase and multicomponent flows are simulated in order to validate components and systems under realistic conditions. The test bench is funded under the ERDF program as part of the European COVID-19 response measures and significantly expands the TFD's research infrastructure.

The newly developed test bench will be integrated into the existing modular test bench environment of the PAE system at CMG and will enable investigations of components for fuel cell systems with a power output of up to 600 kW. Key functions include controlling the inlet conditions of pressure, temperature, and mass flow, as well as providing variable relative humidity between 0 and 100%. In addition, the test bench can generate droplet-laden flows to realistically simulate multiphase phenomena and provide process gases such as hydrogen, nitrogen, helium, or air in freely definable mixing ratios. Contaminants and impurities – such as CO, NOx, or NH₃ – can also be introduced in a targeted manner to test the robustness and performance of the test specimens.

In addition, the system enables the simulation of pressure loss in a fuel cell stack and the use of an inline analysis system to measure moisture content, process gas composition, and potentially harmful gases. The electrical connection includes DC power supply and power measurement technology on the AC and DC sides, allowing electrothermal and mechanical investigations to be combined. This allows recirculation fans, cathode-side air supply systems, and other FC components to be analyzed under realistic conditions in terms of their operating behavior, efficiency, and structural resilience. PastA² thus creates a versatile research platform that significantly accelerates the development and validation of future fuel cell technologies.

The project is managed by the Institute for Turbomachinery and Fluid Dynamics.