Question 8.9: SAE 10 oil is flowing through a pipe line at a velocity of 1...

Introduction to Fluid Mechanics and Fluid Machines

SAE 10 oil is flowing through a pipe line at a velocity of 1.0 m/s. The pipe is 45 m long and has a diameter of 150 mm. Find the head loss due to friction. [ρ = 869 kg/ $m^{3}$ and μ = 0.0814 kg/m . s]

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h_{f}=\frac{f l V^{2}}{2 g D}

In order to know f, first we have to calculate Re.

Re =\frac{\rho V D}{\mu}

=\frac{(869)(1)(150 / 1000)}{0.0814}=1601.35

Since Re < 2000, the flow can be assumed to be laminar and

f = 64/Re = 64/1601 = 0.04

So, $h_{f}=\frac{(0.04)(45)(1.0)^{2}}{(2)(9.81)(150 / 1000)}=0.612$ m

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