Local and Global Entropy Generation of Topographically Optimized Porous Reactors in Reaction-Diffusion Systems Considering Coupling Effects between Heat and Mass Transfer

As the automotive sector shifts towards cleaner and more sustainable technologies, fuel cells and batteries have emerged as promising technologies with revolutionary potential. Hydrogen fuel cell vehicles offer faster refueling times, extended driving ranges, and reduced weight and space requirements compared to battery electric vehicles, making them highly appealing for future transportation applications. Despite these advantages, optimizing electrode structures and balancing various transport mechanisms are crucial for improving PEFCs’ performance for widespread commercial viability. Previous research has utilized topology optimization (TO) to identify optimal electrode structures and attempted to establish a connection between entropy generation and topographically optimized structures, aiming to strengthen TO numerical findings with a robust theoretical basis. However, existing studies have often neglected the coupling of transport phenomena. Typically, it is assumed that a single force corresponds to a specific flux, such as a temperature gradient for heat transfer (following Fourier’s law) or a concentration gradient for mass transport (following Fick’s law). From a non-equilibrium thermodynamics (NET) perspective, multiple forces contribute to fluxes in electrochemical systems. This study aims to explore the local and global entropy generation of topographically optimized porous reactors in reaction-diffusion systems, considering the coupling effects between heat and mass transport. The results reveal a tree-like structure as the optimized design for porous reactors. This heterogeneous structure exhibits minimal global scaled entropy generation and the most uniform local scaled entropy generation. Furthermore, the study distinguishes and discusses entropy generation from different mechanisms.