Floating Type Tidal Current Power Station to Have Counter-Rotating Type Hydroelectric Unit on Board

Abstract

The authors have proposed the counter-rotating type hydroelectric unit in which two stage runners successfully counter-rotate the inner and the outer armatures of the peculiar generator. This paper proposes the optimum profile of the floating type tidal current power station to have this hydroelectric unit on board. The runners are installed in the vertical passage where the flow runs downward. The downward flow is caused by the pressure difference between the flat upper-wall and the convex down-wall of the runner housing submerged. The hydrodynamic characteristics are fundamentally investigated and discussed to give effectively the tidal current energy to the runners. Resultantly, the optimum profile is (1) to make the front and the rear ends of the runner housing dress with the brim edges, (2) to set the semicircular fence at the outlet of the runner passage, and (3) to equip with the flow guide of the circular arc around the runner housing.