Study on high pressure design of contra-rotating small hydroturbine

It is requested that the hydroturbine is small size and high performance. Therefore, we adopted contra-rotating rotors, which can be expected to achieve small size and high performance. However, when the rotors become smaller, the output power of conventional contra-rotating rotors, which is composed of axial flow rotors, is very low. In order to achieve small size and high output power, we propose new type contra-rotating rotors, which is composed of a hybrid rotor and a centrifugal rotor. In this research, we investigate performance of the new type contra-rotating small hydroturbine model by the numerical analysis. We report on the influence of deflection angle on the performance and internal flow condition.