Page 4of 8A5MarksFigure QA5,which is on a separate sheet to be handed in with your answer booklet,shows the head vs flowrate pump curve at a fixed speed for a centrifugal pump.The fluid being pumpedis water.
The pump moves water of density = 1000 kg/m3through a circuit composed of a system of pipes of 100mm internal diameter, with bends, junctions and valves.
The head loss hL(meters of water head) in the system is assumed to be a function of the velocity head in the pipes, given byℎ𝐿=5+𝑘(𝑉22𝑔)And in this casethe effective multiplier is 𝑘=1.2
(i)Determine the operating point by expressing the system characteristic as a function of the flow rate, tabulating atleast 3 combinations of system head and flow rate and plotting the curve on your question paper.
(ii)Determine the power output from the pump at this operating point.Assuming that the overall efficiency of the pump is 70%, determine the shaft power required from the drive motor.
(iii)Giving clear reasons, identify those parts of the pump and other parts of the system at which damage bys water. might occur.
