QUESTION 5 (a) Show that in a pipe flow problem, the Colebrook-White equation to calculate Darcy friction factor can be

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Question 5 A Show That In A Pipe Flow Problem The Colebrook White Equation To Calculate Darcy Friction Factor Can Be 1 (729.42 KiB) Viewed 13 times

QUESTION 5 (a) Show that in a pipe flow problem, the Colebrook-White equation to calculate Darcy friction factor can be written in the form V = -2 (d) 2gDhf ks log L 2.51 v (3.7D D√√2gDh/L) + (V= flow velocity, g = gravitational acceleration, D = pipe diameter, h = head loss due to friction, ks =surface roughness, v= kinematic viscosity, L = length of pipe) (6 marks) (b) A 100mm diameter pipe with a circular section carries water at a flow rate of 0.014m³/s. If the dynamic viscosity of water is 8.90 x 10-4Ns/m² at 25 degrees Celsius and the surface roughness of the pipe is 0.1mm, determine the value of the friction factor using the Moody Diagram given at the end of the exam paper. (Attach this sheet showing your work clearly, to the answer script). (5 marks) (c) A pipeline 10km long, 250mm diameter with a roughness (Ks) of 0.06mm conveys water from a reservoir (free water level 300m AOD) to another reservoir (free water level 150m AOD). Assuming the pipe remains full estimate the discharge using the HRS charts given at the end of the exam paper. Assume an entry loss coefficient of 12.5 and exit loss coefficient of 10.0. (Attach the HRS sheet showing your work clearly, to the answer script). (7 marks) Briefly explain where head losses other than frictional head loss are encountered in pipe systems and how to take account of these losses in pipe flow calculations. (2 marks)