Question

A 3-ft-diameter duct is used to carry ventilating air ( , ) into a vehicular tunnel at a rate of 11000 ft3/min. Tests show that the pressure drop is 1.2 in. of water per 1500 ft of duct. What is (a) the value of the friction factor for this duct and (b) the approximate size of the equivalent roughness of the surface of the duct

Answer 1

a) Friction factor for this duct = 0.0239

b) ε = 0.006 ft

Step-by-step explanation:

Given data :

Flow rate = 11000 ft^3 /min

Pressure drop = 1.2 in per 1500 ft of duct

a) Determine the value of the friction factor for this duct

Friction factor for this duct = 0.0239

b) Determine the approximate size of the equivalent roughness of the surface of the duct

ε = 0.006 ft

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