Effect of sizing of a Savonius type vertical axis micro wind turbine

The primary objective of this paper is to study the effect of sizing of a multi-bladed Savonius rotor on power output. Initially, a base model of the micro wind turbine with 8, 16 and 24 blades with rotor diameter of 300 mm and blade length of 160 mm with a diameter of 40 mm was designed and its power outputs were measured over a range of wind speeds using a wind tunnel. Then the outputs were compared with the modified design by doubling the diameter of the rotor and the length and radius of the blades. Additionally, the output power from the base model was compared with the power outputs of another modified design by keeping the rotor diameter and blade length constant (300 mm and 160 mm) but varying the blade diameters (20 mm, 40 mm and 80 mm) respectively. Results show that the average power increased by about 80% when comparing the base model and double size for all 3 sets of blades (8, 16, 24 blades). It is also found that the power increased about 50% when the diameter of the blade is scaled up by double the size. (C) 2017 The Authors. Published by Elsevier Ltd.