water flows through a pipe of diameter 300 mm with a velocity of 5 m/s. If the co-efficient of friction is given by f = 0.015 + (0.08/ (Re) 0.3) where Re is the Reynolds number, find the head lost due to friction for a length of 10 m. Take kinematic viscosity of water as 0.01 stoke.

 

water flows through a pipe of diameter 300 mm with a velocity of 5 m/s. If the co-efficient of friction is given by f = 0.015 + (0.08/ (Re) 0.3) where Re is the Reynolds number, find the head lost due to friction for a length of 10 m. Take kinematic viscosity of water as 0.01 stoke.

 Solution:

Diameter of the pipe, D = 300mm = 0.30 m

Length of the pipe, L = 10 m

Velocity of flow, V = 5 m/s

Kinematic viscosity of water, ν = 0.01 stoke

                                                     = 0.01*10-4 m 2 /s

Head lost due to friction, hf :

Co-efficient of friction,          f = 0.015+ (0.08/ (Re) 0.3) But

Reynolds number,                  Re= ρVD/µ = VD/ν

                                                    = 5*0.3/ 0.01*10-4 = 1.5*106

                                                   f = 0.015+ (0.08/ (1.5*106 ) 0.3)

                                                      = 0.0161