Comparative Performance Evaluation of Savonius Vertical Axis Wind Turbines: Two and Three-bladed Profiles

In recent decades, the environmental impact of energy production has led to growing global efforts to transition from polluting fossil fuels to renewable energy sources, attracting considerable attention from organizations and researchers. This transition is essential due to escalating environmental concerns and the limited availability of fossil fuels. Concurrently, the deployment of wind turbines worldwide has expanded significantly. This study aims to propose an optimal Savonius vertical axis wind turbine design suited for urban applications. Two turbine models featuring different blade numbers and profiles were designed, constructed, and experimentally tested. The turbines comprised double- and triple-blade configurations, utilizing semicircular and Du06-W-200 blade profiles. Performance evaluation focused on key parameters including power coefficient, final rotational speed, power output, tip speed ratio, and time to reach maximum rotational speed. The results demonstrated that the semicircular double-blade turbine delivered the highest final rotational speed of 1433 RPM, approximately 33% higher than the three-bladed semicircular turbine and over 160% higher than the Du06-profiled turbines. It also achieved the highest power coefficient among all turbines tested. The two-blade turbine (Du06-W-200) profile exhibited the fastest acceleration, reaching its final speed in only 11 seconds, twice as fast as the two-bladed semicircular turbine and three times faster than the three-bladed semicircular configuration. While the Du06-profiled turbines showed slightly lower tip speed ratios, the three-bladed semicircular turbine exhibited the most stable power output. These findings indicate that Savonius turbines with the tested configurations are well-suited for urban environments, though their effectiveness depends strongly on local geographical and climatic conditions.