Experimental Investigation of Shaft Mass Variation on the Performance of a Horizontal-Axis U-Type Savonius Wind Turbine under Low Wind Speed Conditions
Hadi Nasbey, Riser Fahdiran, and Aulia Wulandari

Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Jakarta, Jakarta, Indonesia

Abstract

Wind energy is one of the most promising renewable energy resources in Indonesia- however, its utilization remains limited due to relatively low average wind speeds, particularly in Java, which range from approximately 2.7 to 4.5 m/s. This study investigates the effect of shaft mass variation on the performance efficiency of a horizontal-axis U-type Savonius wind turbine designed for low wind speed applications. The research employed an experimental method by developing a prototype consisting of three U-shaped blades made of 0.3 mm clear polyvinyl chloride (PVC), with blade dimensions of 93 cm in length, 16 cm in diameter, and 8 cm in radius. To improve structural stability, each blade was equipped with four supporting ribs. Three different shaft materials with varying masses were tested: aluminum shaft (166 g), stainless steel shaft (453.5 g), and brass shaft (486 g). Experimental testing was conducted under laboratory-scale conditions using a blower and wind tunnel system with wind speed variations ranging from 1 to 10 m/s. The measured output parameters included shaft rotational speed, output voltage, and electric current generated by a DC generator. The experimental results revealed that the stainless-steel shaft (453.5 g) achieved the highest average efficiency of 2.41%, producing an average turbine power output of 2.37 mW at wind speeds between 2 and 6 m/s. The aluminum shaft generated an average efficiency of 1.42% with a power output of 2.37 mW, while the brass shaft produced an average efficiency of 1.96% with a power output of 2.59 mW. These findings indicate that shaft mass significantly affects rotational stability and energy conversion efficiency in low-speed wind turbine systems. This study highlights the potential of modified Savonius turbines for micro-scale renewable energy harvesting applications in low wind speed regions.

Keywords: renewable energy- rotational inertia- Savonius turbine- wind energy conversion- low-speed wind- power efficiency

Topic: Energy and Environmental Physics