2020 Volume 48 Issue 10 Pages 625-632
It is requested that the hydroturbine be a small size and have high performance. Therefore, the contra-rotating rotors are suitable for a small hydroturbine, because it can be expected to achieve compactification of radial direction and high performance. However, a conventional contra-rotating rotor was composed of two axial flow rotors, so it had a specification suitable for high flow rate and low head. In order to achieve small hydroturbine suitable for low flow rate and high head, we propose a new type of contra-rotating rotors, which are composed of a hybrid rotor and a centrifugal rotor. In order to verify the feasibility of the small hydroturbine, we manufactured an experimental apparatus and investigated the performance of the hydroturbine. In the present paper, we compare the experimental results with the numerical analysis results, and the feasibility of the small hydroturbine was examined.
