Lecture 21: Minor loss, kinetic energy correction factor
(Fig. 21c)
It is an experimental observation that .
Therefore,
Or,
(It is left as an exercise to the students to obtain the above–derivation from combined mass, moments, and energy conservations)
Thus, we have shown that,
For a converging channel, viscous loss,
is also estimated as
Note that is the velocity in the converging section and is the cross-sectional area at the section where “Vena-Contracta" (or, the minimum flow area) occurs:
.
is also estimated as
is the velocity in the converging section and 
is the cross-sectional area at the section where “Vena-Contracta" (or, the minimum flow area) occurs: 
