Parameter Optimization of Bionic Hydrofoil System and Its Application in Algal Bloom Control in Plain River Networks

The bionic pumping system can effectively improve the hydrodynamic conditions in plain river networks, thereby mitigating the frequent algal blooms in these regions. This study employs numerical simulations to investigate how heave amplitude and chord length affect the hydrodynamic performance of both multi-hydrofoil and single-hydrofoil systems. The operating frequencies for the two configurations are selected by combining these results with the flow velocity threshold required to suppress algal blooms. The results show that the pumping efficiency of the multi-hydrofoil system increases with chord length and heave amplitude, and the optimal parameter combination is c = 0.18W and hmax = 0.7c. For the single-hydrofoil system, efficiency first rises and then falls, peaking at c = 0.16 W and hmax = 0.6c. Under the algal bloom suppression threshold of 0.15 m/s, the multi-hydrofoil system meets the criterion across the entire cross-section at 0.10 Hz, making it suitable for raising flow velocity throughout the water body and for comprehensive bloom suppression. By contrast, the single-hydrofoil system produces an uneven wake with lower velocities in the upper region, so even at higher operating frequencies, it cannot cover the entire cross-section; it is therefore more appropriate for localized velocity enhancement and localized suppression of algal accumulation.