The discharge in m³/s for laminar flow through a pipe of diameter 0.04 m having a centre line velocity of 1.5 m/s is :

Question

Question

This question was previously asked in

JKPSC AE Civil 2009 Official Paper

Answer 1

Explanation:

Concept: Discharge through a pipe for laminar flow can be calculated as, \(Q=v.A \)

where, v = Average velocity through the pipe , A = Area of cross section of the pipe = \(\frac{\pi\,d^2}{4}\) , d = Diameter of the pipe

Average velocity through the pipe in case of laminar flow = \(\frac{Center\,line\,velocity}{2}\)

Explanation: given, Diameter of the pipe, d = 0.04 m , centre line velocity, v = 1.5 m/s

∴ Average velocity through the pipe, v = \(\frac{1.5}{2}=\,\, 0.75\,\,m/sec\)

Discharge through a pipe for laminar flow, \(Q=v.A \) = \(v.\frac{\pi.d^2}{4}\) = 0.75×\(\frac{\pi.0.04^2}{4}\) = \(\frac{3\pi}{10,000}\) m³/sec.