Determination of the optimal blade geometry and efficiency evaluation of a gravitational vortex micro hydropower plant with a conical basin

The growing global demand for energy is stimulating the rapid development of low-head micro hydropower plants. Currently, scientific research aimed at increasing the energy efficiency of gravitational vortex micro hydropower plants is actively being carried out in various regions of the world. Within the framework of this study, the effect of turbine blade geometry on the energy efficiency of three turbine models designed for gravitational vortex micro hydropower systems was analyzed. The geometry of the basin and turbine components was digitally modeled using ANSYS 2022R1 (Fluent Flow) software. The numerical simulations were performed using Computational Fluid Dynamics (CFD) with the SST k-ω turbulence model. According to the CFD analysis results, three turbines with different geometries  (a, b, and c) were tested at rotational speeds ranging from 20 to 150 RPM, and the highest efficiency was observed in the c) turbine model. To ensure perpendicular impact of the water flow onto the turbine blades inside the basin, the c) turbine was tilted by 45° relative to the vertical axis, which increased its energy efficiency to 85,5%. To validate the results,  3D physical prototypes of the turbines were fabricated and tested under real conditions. As a result, the c) turbine model inclined at 45°, which showed the highest efficiency in the CFD simulation, also achieved a high efficiency of 79,6% in experimental testing.

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