Water is flowing fully in a circular pipe of diameter 1 m with a velocity of 10 m/s. If loss of head due to friction is 0.2 m for a pipe length of 10 m, what is the coefficient of friction (assume acceleration due to gravity g = 10 m/s²)

Concept:

Head loss due to pipe friction (h_f) is given by:

where, f = friction factor, l = length of pipe, V velocity of the fluid in the pipe, d = diameter of the pipe.

Also friction coefficient (f') is given by:

Calculation:

Given:

d = 1 m, V = 10 m/s, h_f = 0.2 m, l = 10 m, g = 10m/s²

f = 0.004

Now the coefficient of friction can be calculated as,

f' = 0.001

Hence the required value of coefficient of friction is 0.001.