Daniel Aderson Sinaga, Zainal Arifin, Singgih Dwi Prasetyo, Solikin Andriyanto, Muhamad Dwi Septiyanto, Syamsul Hadi
This study investigates blades of varying geometries in the context of a two-stage Gravitational Water Vortex Turbine (GVWT). The objective was to identify the optimal blade shape and radius yielding the best rotational speed, mechanical power, and efficiency for a two-stage vortex turbine. Specifically, the study examined parameters such as the Savonius shape and curvature, utilizing different blade ratios on two separate shafts. The turbines were configured with a telescopic system positioned at a distance of 10 cm apart. Each variation was subjected to loads ranging from 0.5 kg to 2 kg. Various performance metrics—rotational speed, torque, and water height—were assessed following load adjustments. Turbine Stage 1, employing the Savonius blade, achieved an optimal mechanical power output of 12.4 W, while Turbine Stage 2, utilizing a curved blade, reached a maximum mechanical power of 11.1 W. The Savonius blade demonstrated higher torque, operating more efficiently under greater loads. Notably, the water vortex with a larger air core experienced distortion caused by the turbine, leading to unstable flow. In contrast, implementing curved blades with a ratio of 0.5 provided the water vortex ample space to flow, resulting in a more stable vortex formation. Thus, carefully considering the optimal contact area and blade geometry is essential to minimize water vortex distortion in each turbine. ©2025 The authors.
Department of Mechanical Engineering, Faculty of Engineering, Universitas Sebelas Maret, Surakarta, 57126, Indonesia; Department of Power Plant Engineering Technology, Faculty of Vocational Studies, State University of Malang, Malang, 65145, Indonesia
