Water to a residential area is transported at a rate of 1.5m3/s via 70-cm-internal-diameter concrete pipes with asurface roughness of 3 mm and a total length of 1520 m. In order toreduce pumping power requirements, it is proposed to line theinterior surfaces of the concrete pipe with 2-cm thickpetroleum-based lining that has a surface roughness thickness of0.04 mm. There is a concern that the reduction of pipe diameter to66 cm and the increase in average velocity may offset any gains.Taking Ï = 1000 kg/m3 and v = 1 ×10–6 m2/s for water, determine the percentincrease or decrease in the pumping power requirements due to pipefrictional losses as a result of lining the concrete pipes. (Roundthe final answer to one decimal place.)
