Hydro-turbine runner

摘要

A turbine, disposed in water flowing therethrough, includes a hub and associated runner blades. Each blade comprises an inner surface and a distal outer surface, a leading edge and a trailing edge separated by a water directing surface. Each blade is rotatable relative to the hub about a blade rotational axis. The hub includes a spherically-shaped outer surface in a region of the hub swept by the inner surface of the blades when the blades are rotated from maximum to minimum pitch. The hub may also be associated with blades in which the chord is reduced in the root region of the blade. The turbine may also include seals attached to the blade inner surface and an essentially spherically-shaped discharge ring to improve certain turbine parameters such as cavitation, efficiency, flow disturbance, and fish survivability.