水車の摩擦抵抗低減に関する研究

抄録

Friction loss on the flow passages accounts for about half of all losses of the hydraulic turbine. In the performance enhancement of the hydraulic turbine, the reduction of the shape loss has been performed mainly. However, it is more necessary to reduce friction loss to improve efficiency. The present paper deals with experimental investigation using two kinds of surface-treated material coated on a flat plate fixed in the rectangular channel in order to observe effective skin-friction reduction. As the results it was seen that the organic hydrophilic coating decrease the skin-friction drag. Consequently it was confirmed that in the model test the turbine efficiency improved within a certain Reynolds number by the runner applied an organic hydrophilic coating to blade surfaces.