抄録
A two dimensional Darrieus-type turbine has been proposed for hydropower utilization of extra-low head less than 2 m. In a practical use of Darrieus-type hydro turbine, head and flow rate may be varied temporally and seasonally. Considering that the cost advantage is required for the low head hydro turbine system, the Darrieus turbine should be operated with high efficiency in the wider range of flow rate by an additional device of simple mechanism. In the present paper, a countermeasure against performance deterioration in low flow rate condition is proposed. It is an adjustment of inlet nozzle section by lowering the inlet nozzle height to obtain the preferable inlet velocity. Therefore, the effect of spanwise partial inlet flow on the turbine performance, correlation with downstream water level, and self-starting characteristics are experimentally investigated. Finally, an effective modification of inlet nozzle height over flow rate variation is shown.
