Hydraulic Efficiency
The power input P in the form of kinetic energy in the jet, is:
defined as the ratio of output power to input power is:
with a maximum value:
In the absence of friction, the relative speed is not reduced by passage over the bucket surface, so the value of k would then be unity.
Moreover, the lowest conceivable value of
corresponding to
So the factor
could ideally just reach the value 2
The maximum ideal efficiency,