On Sustainable Power Generation from a Three-Bladed Archimedean Screw Turbine - A Computational Fluid Dynamics Analysis

As the demand for sustainable energy continues to upsurge, there is a rising interest in alternative hydropower technologies that can operate efficiently in low-head water sources with heads below 1 m. One such promising alternative is the Archimedean Screw Turbine (AST) which is known for its simple design, environmental compatibility, and adaptability to varying flow conditions. Previous researches have reported AST achieving high efficiency under moderate to high heads (1 - 5 m) with longer screw lengths exceeding 5 m. However, the performance of AST in setups with shorter screws, low flow velocities and lower heads remain relatively unexplored. This study therefore aims to assess the performance of a three-bladed AST with screw length of 1 m operating under low-head and low flow velocity conditions, using computational fluid dynamics (CFD) simulations. The simulation of the scaled down AST setup shows promising results with high efficiency. Key parameters such as inlet flow velocity (1, 3, and 5 ms<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup>), radius ratio (0.33, 0.38, 0.50), and screw inclination angle (25° and 30°) are varied to assess their impact on efficiency and power output. The optimal configuration is found at an inlet flow velocity of 3 ms<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup>, a radius ratio of 0.33, and 25° inclination, achieving the maximum efficiency of 76.3% and a peak power output of 36.01 kW. Torque variations follow a bell-shaped trend, increasing with velocity up to an optimal point before decreasing due to turbulence. The findings highlight AST as an effective renewable energy solution, particularly for low-head water sources, offering reliable performance with minimal environmental impact and contributing to sustainable energy development.