Study on a Contra-Rotating Small Hydro Turbine

Renewable energy attracts a great deal of attention from the point of view of energy problem and global warming by CO2 emission. Small hydropower is recognized as a new energy in Japan. There are many places to install pico hydropower in irrigation water channels and small rivers, so there is a strong demand for small hydro turbine to minimize environmental impacts. In this research, contra-rotating rotor and low solidity rotor were applied for high performance and stable operation of small hydro turbine. In this paper, performance and internal flow of contra-rotating small hydro turbine were clarified by numerical analysis and the possibility of the contra-rotating rotor for small hydro turbine used as electrical appliance and a control method to improve the performance were considered.