Investigation of transport-reaction dynamics and local/global entropy production in topology optimization of two-species reaction-diffusion systems

There is a growing body of research on the enhancement of porous reactors through the modification of their structures. So far, however, there has been little elucidation on how altered spatial structure might be beneficial to reducing irreversible losses. To explain the optimization procedure from a theoretical basis, this study aims to investigate the dynamics of rate and transport processes in a reaction-diffusion system with two-species operating under a steady-state mode. A topology optimization method is employed to increase the overall reaction rate by modifying porosity distribution. Additionally, an entropy generation model is developed to examine the irreversibilities of the system. Based on this model, the local and global rates of entropy production in the system are evaluated, and contributions by various mechanisms are separately quantified. The results show that an optimal porosity distribution can boost the system performance by 57% through formation of proper primary and secondary diffusion channels.