Water to a residential area is transported at a rate of 1.5 m³/s via 70-cm-internal-diameter concrete pipes with a surface roughness of 3 mm and a total length of 1500 m. In order to reduce pumping power requirements, it is proposed to line the interior surfaces of the concrete pipe with 2-cm-thick petroleum-based lining that has a surface roughness thickness of 0.04 mm. There is concern that reducing the pipe diameter to 66 cm and thereby increasing the average velocity may offset any gains from reducing roughness. Assuming values of p = 1000 kg/m² and v = 1 × 10* m³/s for water, determine the percent decrease (or increase) in the pumping power requirements due to frictional losses as a result of lining the concrete pipes.

The drinking water to a village is supplied from a reservoir which is 475 m above and 25 km away from the village. The water is transported from the reservoir to an open-top storage tank in the village via a circular pipe with a diameter of 18 cm and a roughness of 0.15 mm. The population of the village is 1500 people. There are two valves (K=2) and five 90° elbows (K=1.5) along the pipe. Assuming that an average person in the village consumes 225 L/day, determine the power (kW) of the pump needed to transter the water from the reservoir to the storage tank. You can take the density and viscosity of water as 1000 kg/m and 0.001 kg/m s, respectively, and you can neglect the inlet and exit losses and the kinetic energy correction factor effects.

In a hydroelectric power plant, water at 20°C is supplied to the turbine at a rate of 0.6 m3/s through a 200-m-long, 0.35-m-diameter cast iron pipe. The elevation difference between the free surface of the reservoir and the turbine discharge is 140 m, and the combined turbine–generator efficiency is 80 percent. Disregarding the minor losses because of the large length-to-diameter ratio, determine the electric power output of this plant.

Water in a reservoir at 20°C enters into a 5 cm diameter horizontal cast iron pipe through a sharp- edged entrance (loss coefficient, K = 0.5) at a flow rate of 0.24 m³/min. The water then flows through a turbine and a wide-open globe valve before discharging into the atmosphere. The water level in the reservoir is 40 m above the pipe entrance, and the total length of pipe is 125 m. Determine the power extracted by the turbine.

Water to a residential area is transported at a rate of 1.5 m3/s via 70-cm-internal-diameter concrete pipes with a surface roughness of 3 mm and a total length of 1500 m. In order to reduce pumping power requirements, it is proposed to line the interior surfaces of the concrete pipe with 2-cmthick petroleum-based lining that has a surface roughness thickness of 0.04 mm. There is a concern that the reduction of pipe diameter to 66 cm and the increase in average velocity may offset any gains. Taking ? = 1000 kg/m3 and ? =1× 10−6 m2/s for water, determine the percent increase or decrease in the pumping power requirements due to pipe frictional losses as a result of lining the concrete pipes.

Water is transported by gravity through a 10-cmdiameter 550-m-long plastic pipe with an elevation gradient of 0.01 (i.e., an elevation drop of 1 m per 100 m of pipe length). Taking ? = 1000 kg/m3 and ? = 1 × 10−6 m2/s for water, determine the flow rate of water through the pipe. If the pipe were horizontal, what would the power requirements be to maintain the same flow rate?