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Abstract
Abstract. Introduction. Improving the efficient utilization of renewable energy resources, advancing environmentally friendly electricity generation, and enhancing the performance of micro-hydropower plants are among the key challenges in the global energy sector. Optimizing the blade geometry of Cross-Flow (Banki) turbines, which are widely employed under low-head and variable operating conditions, is of considerable scientific and practical importance for improving their hydraulic efficiency.
Methods and Materials. In this study, four blade shakle configurations-flat, rounded, sharp, and aerodynamic-of a Cross-Flow (Banki) turbine were numerically investigated using two-dimensional (2D) Computational Fluid Dynamics (CFD) simulations in ANSYS Fluent. The Shear Stress Transport (SST) k-ω turbulence model was employed to accurately capture flow separation, recirculation, and turbulent flow phenomena. Simulations were performed under a constant hydraulic head of 10 m over a runner rotational speed range of 270-940 rpm. Hydraulic torque, hydraulic efficiency, water volume fraction, pressure distribution, and velocity fields were evaluated to assess the influence of blade geometry on turbine performance.
Results. The numerical results demonstrated that the aerodynamic blade shakle provided superior hydraulic performance compared with the other blade configurations. A maximum hydraulic efficiency of 83.5% was achieved at a runner speed of 800 rpm. The improved performance was primarily attributed to enhanced flow attachment along the blade surface, reduced vortex formation, and lower pressure losses at the outlet. Although the sharp blade shakle exhibited competitive performance within a limited range of optimal rotational speeds, the flat and rounded blade shakles generated significantly higher turbulence intensity and larger recirculation zones, leading to reduced hydraulic efficiency.
Conclusion. The findings confirm that the hydraulic performance of Cross-Flow (Banki) turbines is strongly influenced by blade geometry. The aerodynamic blade shakle effectively suppresses flow instabilities and improves energy conversion efficiency throughout the two-stage energy transfer process. Furthermore, the study demonstrates that CFD-based numerical modeling is a reliable approach for the design and optimization of Cross-Flow turbines. The obtained results provide a valuable scientific and engineering basis for the development of high-efficiency turbines intended for micro-hydropower applications.
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Copyright (c) 2026 Safarov, A.B., Pirimov, R.R., Nematov, B.N., Choriyev, A.I. (Muallif)