Question

What is the formula for discharge through the pipe?

(a) Q = Cd x A

(b) Q = Cd x A x \(\sqrt{2gH_L}\)

(c) Q = Cd x \(\sqrt{2gH_L}\)

(d) Q = A x \(\sqrt{2gH_L}\)

This question was posed to me in an interview for internship.

The query is from Regulation Modules in chapter Regulation Modules and Canal Structure of Irrigation Engineering

Answer 1

The correct answer is (b) Q = Cd x A x \(\sqrt{2gH_L}\)

The explanation is: After knowing the velocity through the pipe, we can calculate discharge using the relation discharge = velocity x area. Mathematically q = V x A, therefore q = Cd x A x \(\sqrt{2gH_L}\) where q = discharge, Cd = coefficient of friction, A = area of pipe, HL = difference of head between FSL of distributary and FSL of water course.