NUMERICAL AND EXPERIMENTAL INVESTIGATION OF THE EFFECT OF A CIRCULAR CYLINDER AS PASSIVE CONTROL ON THE SAVONIUS WIND TURBINE PERFORMANCE

Abstract

This study aims to ensure the role of the circular cylinder as a passive control in creating flow interaction between the circular cylinder and the returning turbine blade behind it, and this new concept is enabled to improve the performance of the Savonius turbine. It was carried out numerically and experimentally by installing a circular cylinder on the upstream side of the returning turbine blade with a ratio of the cylinder diameter to the turbine rotor diameter (d/D) of 0.54. The cylinder is installed at a position relative to the rotor diameter (S/D), which remains constant at 1.4, and it is operated at Reynolds number (Re) = 140,000. The results indicate an excellent agreement between numerical and experimental results, where the relative deviation of less than 1.0% is practically negligible. Both results have also agreed that the presence of the circular cylinder as passive control on the upstream side of the returning turbine blade can increase the efficiency of the Savonius turbine. Increases in maximum power coefficient of about 8.8% and 10.2% have been obtained for numerical and experimental work.