Study for High Performance of High Pressure Small Hydroturbine

Small hydropower generation is one of important alternative energy, and potential of small hydropower is great. Efficiency of small hydro turbines is lower than that of large one and high performance is required. 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 are 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. In this report, we investigated of the influence of the deflection angle and blade number related to the load of rotor.