c) Figure Q5(c) on page 6 shows a particular pump-system-efficiency curve for a specific pump operating at 20C, with water as the working fluid (density 1000 kg/m3) (i) In general terms, explain this figure (Figure Q5(c)). What is meant by the 'Pump Curve', 'System Curve' and 'Efficiency' and how are these sorts of data generated? In particular also, discuss why the efficiency peaks at intermediate flowrates. [5 marks] Q5(c) Integrated pump performance curve, showing the 'Pump' and 'System' curves (left hand axis) and 'Efficiency' (right hand axis) against flowrate. (ii) Calculate the Net Positive Suction Head (NPSH) for conditions at the pump's duty point, if it is placed 2m below the top surface of a reservoir that is open to the atmosphere (noting 1atm=101.3kPa ). It can be assumed that the gravitational constant, g=9.8ms2, and the vapour pressure of water at 20C is 2.3kPa. Would this pump suffer significant suction issues? Hint: use the NPSH equation below. [5 marks] NPSH=gP0+h0hfgPv