水中駆動衝動タービンに用いるノズル仕様の検討

抄録

This study was focused on influence of nozzle shape and its layout on the performance of submerged impulse turbine. Because ambient water will affect the water jet issuing from a nozzle. It is considered that jet behavior will be drastically different between submerged and non-submerged jet. Two types of cutting angle at the end of the pipe nozzle, right angled and sharp edged, were tested. Reynolds number based on the nozzle diameter and jet velocity at the exit is 10⁵. PIV measurement was conducted for free jets and their velocity fields were compared. And the turbine performance was investigated for the nozzles and different impinging length from the nozzle exit to runner. As a result, it is revealed that the performance increases with decrease of the impinging length while the nozzle end shape has no influence on the performance.