“…In the fully-coupled model, the cell-level fine model is coupled with the stack-level model by providing the electrochemical heat source term and mass source terms of O2, H2, and H2O, while the stack-level model provides the distribution of π, π π 2 , π π» 2 , π π» 2 π as the boundary conditions for cell-level models. To avoid computing the cell-level non-uniform distributions of mass and heat sources which do not significantly affect the stack-level temperature and mass distributions, the APA data-driven method, proposed by our group in [9], is used to build surrogate models for single cells. In other words, the celllevel fine model is simulated under several sampling points (different values of π ππ£ , πΌ, πΉπ, π π 2 ,ππ£ ), and the simulation results are used to identify the relationships between π βπππ‘ , π πππ π ,π 2 , π ππππ and π ππ£ , πΌ, πΉπ, π π 2 ,ππ£ , formulated as follows.…”