(Solved): Question 1 [25 marks] A Valve H B Water is being drained slowly from tank A to tank B by a half op ...

Question 1 [25 marks] A Valve H B Water is being drained slowly from tank A to tank B by a half open gate valve with a coefficient of friction loss of 0.45. The pipe used to drain the tank is a rusted, steel pipe with a diameter of 9 cm and a length of 21 meters. At a certain time, the pipe was to be replaced with a thick, cast iron pipe with diameter of 150 mm. Due to some design restrictions, the engineers decided to replace only the 2/3 of the old pipe with the new one. Two bends were fitted to accommodate tank B at a lower level and allow the flow of water under gravity. Calculate the difference in the water levels of the tank that will produce a flow rate of 10 litres/s. Assume that entry and exits of the pipe are both re-entrant and the coefficient of the bends is equal to 0.2 and 0.3 consecutively. (u = 1 × 10-³ Pas)