E4.7 Skin Friction Losses

Example 4.7: What is the skin frictional loss when water is flowing at 5 ft/s through a horizontal 100 ft long pipe having inside diameter of 2.067 in and roughness 0.00015 ft. Use the following data:

Density of water = 62.30 lb/ft³, viscosity of water = 6.583 ´ 10^-4 lb/(ft·s)

Roughness of the pipe = 0.00015 ft

Assume that inlet and exit points are at the same elevation and entrance and exit losses are negligible.

Solution:

Diameter of the pipe, d = 0.17225 ft

Reynolds number, Re (Equation 4.12):

Relative roughness, RR (Equation 4.13):

Fanning friction factor, f (Figure 4.3) = 0.0056

Frictional losses, h_f (Equation 4.11):