Computational Fluid Dynamics Analysis of hydrogen ejectors for anodic recirculation in PEMFC Systems.

The anode subsystem of a PEM fuel cell (PEMFC) plays a crucial role in ensuring the efficient and stable operation of the overall system. To enhance the efficiency of the PEMFC, it is essential to minimize the energy consumption of auxiliary subsystems, such as the mechanical compressor used in the anode recirculation loop. One promising approach is the use of passive recirculation through an ejector, which operates without any external power consumption. However, the design of ejectors is highly complex due to their performance sensitivity to the operating conditions of the PEMFC system. To better understand their behavior and identify potential performance improvements, computational fluid dynamics (CFD) simulations can be employed. These simulations provide valuable insights into the fluid flow characteristics, their dependence on operating conditions, and their interrelation with the geometric parameters of the device. In this work, particular attention is devoted to the modeling of ejectors in ANSYS Fluent, including the meshing strategy, the selection and influence of turbulence models, as well as solver settings and solution controls. The ultimate goal is to develop and validate a reliable model capable of accurately representing the ejector’s performance under various operating conditions.