solution

Two water reservoirs are joined by a sharp ended flexible pipe 100 mm in diameter and 36 m long. The ends of the pipe differ in level by 4 m. The surface level of the upper reservoir is 1.8 m above the pipe inlet whilst that of the lower reservoir is 1.2 m above the pipe outlet. At a position 7.5 m horizontally from the upper reservoir, the pipe is required to pass over a barrier. Assuming that the pipe is kept straight between the inlet and the top of the barrier and that the average friction factor is 0.01, find the greatest height to which the pipe may rise at the barrier if the absolute pressure in the pipe is not to drop below 40 kN/m2. You may ignore losses at the bends in the pipe but all other losses should be included in the calculation. Use values for k as given in the lecture notes. Take atmospheric pressure as 1.013 bar. (ans.: 6.04 m above inlet)