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Question 5 (a) Describe the circumstances which might result in water hammer being induced in a system and discuss, in the context of a water distribution system, the methods which might be used to minimise its effects. 10 Marks (b) An oil company wishes to construct a pressurised pipeline of 350 mm diameter to convey freshwater, of bulk modulus 2.10X10° Pa from a desalination plant to a refinery at a rate of 200 l/s and with a pipe period of 4 seconds. Calculate the corresponding theoretical surge pressure induced within the pipeline by the complete closure of an on- line valve in 8 seconds. The valve generates non-uniform retardation of type R = Atº.65, The steel pipe has 5 mm thick walls, a Young's modulus of 2.1x1011 N/m2 and Poisson's ratio of 0.28. Calculate the pressure transients at 1 second intervals at the valve for the first 12 seconds after the valve starts close. Assume that pipe is longitudinally restrained. 15 Marks heedrise in pressure = 169.23.m May