Impacts of Pulsating Flow on Topologically Optimized Porous Reactors in Convection-Diffusion-Reaction Systems

Topology optimization (TO) in electrochemical systems has recently attracted many researchers. Previous studies suggested minimal performance differences between 2D and 3D designs, indicating that 2D models suffice to enhance performance, especially in unidirectional flow scenarios. A later study found that the concentration distribution in an optimized 2D flow system differed from that in a unidirectional flow system. We posited that pulsating flow could further enhance the performance of such systems. First, we initiated TO for a diffusion-reaction system in a steady state. The optimized structure obtained from this process served as the foundation for subsequent investigations involving a pulsating flow source in convection-diffusion-reaction systems. We introduced two different systems with distinct flow natures: one characterized by a flow nature of 1D and the other by a flow nature of 2D. The results demonstrated that the optimized structure with a heterogeneous distribution consistently outperformed its homogeneous counterpart in both systems. The introduction of a pulsating flow source had no significant effect on the system with a flow nature of 1D. However, in the system characterized by a 2D flow nature, the pulsating flow significantly improved overall reaction performance. This enhancement was attributed to substantial species consumption at the inlet, resulting in a non-linear 1D projected concentration distribution. The pulsating flow effectively pumped the species to reach the farthest end, enhancing the overall reaction. The degree of improvement increased with the frequency of the pulse. While the optimal frequency for 2D flow systems remains undetermined, further effort is needed for improvement.