A 4.42km long pipeline of cast iron discharging water at a rate of 45L/s through a valve placed at the downstream end. The internal diameter of the pipe is 20cm and the wall thickness is 15mm. (Ewater=2.17*109 N/m2; Ep=16*1011 N/m2 and Poisson ratio of cast iron pipe = 0.25). Assuming the rigid pipe wall,
(a) If the valve is suddenly closed in 2 secs completely, calculate the magnitude of the surge pressure generated by the sudden and complete valve closure. [6 marks]
(b) Sketch the variation in surge pressure at the valve and at the mid-point of the pipeline after valve closure