Francis turbine for the generation of hydro-electricity has blade profile ratio minimizing trailing edge vortices

摘要

A Francis turbine has a rotating array of turbine blades rotating on a hub and enclosed within a rotating shroud. Each blade has a root, a tip, a leading edge and a trailing edge. The distance Rc between the axis of rotation (1) and the shroud (7), divided by the distance Rb between the axis of rotation (1) and the root end (14), is a ratio between 0.2 and 04.