Abstract: A Francis turbine runner including a shortened band length and a shortened blade length combined with a reversed runner blade leading edge having a junction of the leading edge with the band forerunning a junction of the leading edge with the crown in the rotational direction, and a bandless runner including a shortened periphery length and a shortened blade length combined with a reversed runner blade leading edge having a corner of the leading edge at the outer periphery of the runner that is in advance of where the leading edge joins the crown in the rotational direction. Additional feature includes an inverted trailing edge curvature design on the runner blade that further shortens the blade length.

Abstract: A blade for a runner of a Francis turbine having a throat diameter (Dth), the blade including: a maximum thickness of no less than 0.03 Dth and a leading edge having a maximum lean angle of no less than 45 degrees, wherein the lean angle is defined by a vertical line and the leading edge.

Abstract: A hydro turbine assembly includes a hub configured to rotate about a center axis and configured to be mounted in a water passage. The hub includes an upstream end, a downstream end and an outer surface between the upstream and downstream ends. The hub includes at least three mounting recesses arranged in the outer surface wherein each mounting recess includes a first hub mounting surface and a second hub mounting surface, and the second hub mounting surface is downstream and radially inward of the first hub mounting surface. The assembly includes at least three runner blades each including a base configured to seat in a respective one of the mounting recesses, wherein the base includes a first blade mounting surface arranged to abut the first hub mounting surface and a second blade mounting surface arranged to abut the second hub mounting surface.