Synergistic performance study on energy harvesting and fluid regulation of fish spine wing bionic impeller ball valve

Leakage of long-distance subsea oil and gas pipelines severely endangers marine ecosystems, and unstable power for online monitoring hinders leakage early warning and emergency response. To tackle power shortages for pipelines in deep, polar and high-pressure marine environments and eliminate waste of excess pipeline fluid energy via pressure reducing valves, this paper proposes an innovative fish spine wing bionic impeller energy-harvesting ball valve combining bionic fluid mechanics and mechanical design theories. The impeller adopts a circumferential arrangement with three blades in one group. The blade profile perfectly replicates the streamlined characteristics of dynamic fluid coupling of fish dorsal ridges, breaking the single-curved surface design limitation of traditional impellers. By reconstructing the blade curvature distribution, the coordinated optimization of flow field adaptability and energy harvesting efficiency is realized. Based on CFD numerical simulation, combined with the dynamic mesh method and the SST k-ω turbulence model, the effects of valve opening, tip speed ratio, blade arc angle and helix angle on the comprehensive performance of the energy-harvesting ball valve are systematically investigated, and a comparative analysis with the conventional Savonius impeller is carried out. The results demonstrate that the fish spine wing bionic impeller is capable of improving the flow field distribution inside the valve and reducing turbulent energy loss. Under the optimal tip speed ratio, its peak shaft power reaches 130 W, which is 36.8% higher than that of the conventional impeller. The overall performance is optimal at a blade arc angle of 120° and a helix angle of 0°. Within the full valve opening range of 13%–100%, the bionic impeller outperforms the conventional impeller in both energy harvesting characteristic and flow regulation stability. This design provides efficient and reliable core equipment for surplus energy recovery of intelligent pipeline networks. The bionic structure optimization concept and the design method of variable blade arc angle and helix angle offer a new reference for the performance improvement of fluid machinery, and also provide an efficient and feasible technical scheme for surplus energy recycling in intelligent pipe networks.