Enhancing vertical mixing in Lake Biwa through optimal placement of density flow diffusion devices using genetic algorithms

Abstract The promotion of vertical mixing in lakes plays a crucial role in maintaining water quality and ecosystem stability. This study proposes an optimization method using Genetic Algorithms (GA) to determine the optimal placement of density flow diffusion devices, which are expected to enhance vertical mixing by mitigating stratification and facilitating the exchange of surface and bottom waters. Since the effectiveness of these devices largely depends on their placement conditions, computational fluid dynamics (CFD) were conducted to analyze the flow field of Lake Biwa, and GA was applied to explore optimal device arrangements. The simulation results demonstrated that specific placement configurations significantly enhanced vertical mixing, indicating the potential applicability of density flow diffusion devices. The findings of this study contribute to effective water environment management in Lake Biwa and provide valuable insights into maintaining lake stability through improved vertical mixing.