Question

What is the formula for velocity through the pipe?

(a) Total loss of head = Entry loss + Frictional loss

(b) Total loss of head = Frictional loss + Velocity head at exit

(c) Total loss of head = Entry loss + Velocity head at exit

(d) Total loss of head = Entry loss + Frictional loss + Velocity head at exit

This question was posed to me during an online interview.

My question is based upon Regulation Modules topic in portion Regulation Modules and Canal Structure of Irrigation Engineering

Answer 1

Correct option is (d) Total loss of head = Entry loss + Frictional loss + Velocity head at exit

To elaborate: If the difference in the water level of the distributary and the water course is known then by using the formula total loss of head = entry loss + frictional loss + velocity head at the exit. Mathematically it is represented as HL = 0.5V^2/2g (1.5 + f’ l/d) where l = length of pipe, d = diameter of pipe and f’ = coefficient of friction.