Question 2

Water at 15.6 °C and standard atmospheric pressure flows through a horizontal, galvanized iron pipe (ε = 0.15 mm) at a rate of 0.057 m³/s. You have to use Colebrook equation in solving this question. (a) Determine the minimum pipe diameter if the pressure drop is to be no more than 3.45 kN/m² per 30.5 m of pipe. (b) Plot the minimum diameter required as a function of the flow rate, by selecting the flow rate range from 0.01 m³/s to 0.06 m³/s (c) Discuss the plot in (b). (d) If air flows through the pipe in place of water, discuss its effect on the minimum pipe diameter without further calculation. (e) If a plastic pipe (with zero roughness) is used in place of the galvanized iron, discuss its effect on the minimum pipe diameter without further calculation.