Decorative water fountains consist of a water reservoir and underground piping to and from a pump.
One such system is shown schematically in the figure. The pipe material is PVC(a table is provided). The outlet line from the pump is 18 m and the inlet line to the pump is 20 m. The outlet line leads to the bottom of an annular flow line. The expansion there has a loss of K=2 based on the kinetic energy before the expansion. The annular flow passage has a length L = 180 cm and is bounded by Do=10cm and Di=7cm (use hydraulic radius for the energy loss calculations of such annular flow passage). It is also made of PVC. There is negligible loss at the exit of the annulus; the pressure at that location is atmospheric. Consider all other minor losses following what is in the sketch. What is the pump power required for the flow configuration shown? If the pump-motor combination has an efficiency of 92%, determine the electrical power requirements. If electricity costs $0.05/kWh, determine the cost of running the fountain for 8 hours
NOTES: (1) The flow rate should be enough so the water reaches 1 m as sketched (2)Use the velocity criteria discussed in class to select the PVC pipe diameters.