Water in an open channel flows at a depth of 3.5 m, where the average velocity is 3 m/s. The bed is 12 m above the datum line. Find the total energy in pressure head per unit weight of water at the cross-section at any section.
The total energy or pressure head of liquid in open channel by Bernoulli’s equation is:
H=z+y+\frac{V^{2} }{2g} (i)
Substituting the values of datum head, depth and velocity in Eq. (i), we have
H=12+3.5+\frac{3^{2} }{2×9.81}
H =15.95 m of water