Experimental studies on the effect of obstacle upstream of a Savonius wind turbine

The present studies investigate the performance of a small Savonius vertical axis wind turbine equipped with an upstream obstacle to guide the wind direction. The wind tunnel measurement was carried out in a test facility at the Mechanical Engineering Department, Institut Teknologi Sepuluh Nopember (ITS). The dynamic torque was measured using the brake dynamometer. Several variations of the obstacle orientations were investigated. Two different wind speeds of 2.48 m/s and 7.45 m/s were considered, that correspond to the Reynolds numbers of 30,000 and 90,000, respectively, according to the rotor diameter. It is found from the studies that the mechanical torque and power generated by the rotor are strongly affected by the obstacle. On the other hand, the Reynolds number has no significant impact on the rotor performance.