Abstract
The flow field in a rotating Savonius rotor is measured by particle-tracking velocimetry with conditional sampling technique and is compared with the streak-line pictures visualized by smoke-wire method. The present measurement reproduces well the qualitative nature of the flow field in and around the rotor observed in the streak-line pictures. It is also found that the flow velocity on the advancing blade side is increased with a growth of tip-speed ratio, which is enhanced at small rotor angles by the presence of the Coanda-like flow pattern on the advancing blade. The flow phenomena such as the separation on the convex side of the advancing blade, vortical structure inside the rotor and the development of the wake downstream are clearly indicated in the present velocity-vector diagrams.
