9 Hydraulic Turbines
336
Francis turbine, increasing with specific speed from 0.5 to 2. The Kaplan turbine
with adjustable stator vanes and rotor blades also has a rather flat efficiency curve.
The dependency on flow rate increases if only the rotor blades are adjustable. The
Fig. 9.14 Sensitivity to rotor
or stator angle changes for
reaction turbines
Fig. 9.15 Efficiency versus flow rate of the various turbine types. (Adapted from [3])