Hydrodynamic performance improvement on the hydrofoil using slotted configurations

Hydrofoil is an important component and exerts a significant impact on the performance of hydraulic machinery. Passive flow control can optimize dynamic characteristics and alter turbulent structure around hydrofoil. Slot holds a prominent position due to its efficacy and cost advantage in terms of production and installation. The present study proposes a novel configuration that can enhance the hydrodynamic behavior of hydrofoil. An advanced high-fidelity spectral element method is employed to investigate the hydraulic characteristics of proposed configurations and large-eddy simulation is implemented to model turbulence. The effects of varying slot width, as well as inlet and outlet positions, are systematically examined to explore the flow-field alteration by comparing these configurations to the baseline. The crucial parameters including drag, lift, and pressure coefficients for the slotted configurations are numerically computed, revealing enhancements in the hydrodynamic performance. The optimal slot establishes a connection between the pressure and suction sides, leading to pressure reduction on the suction side and mitigating the risk of cavitation. The upward-directed slot with the outlet positioned away from the tailing and leading-edge vortices outperforms the other configurations. The jet stream of the slot driven by dynamic pressure is vigorous and unstable without one dominant frequency. Furthermore, the slot effectively alters the frequency of fluid-induced forces. These findings hold great promise for the enhancement of hydrofoil design in current energy utilization.