A 7350 m long, 1050 mm concrete pipeline connects an upstream reservoir (water surface elevation 433.3 m) to a downstream reservoir (water surface elevation 423.1 m). A discharge valve at the downstream end is used to control flow; when this valve is fully open, the measured discharge in the pipeline is 920 L/s under the naturally available head difference. (a) Assuming fully developed turbulent flow and that all other local losses are negligible, estimate the loss coefficient k for the fully open valve (assume f = 0.015). (b) Because of increasing urban development, the flow under the natural head difference is considered to be inadequate and it is proposed to increase this flow with pumping. The head- capacity curve for the pump can be approximated by the equation H = 8 – 3.5Q2 in which H is the total dynamic head on the pump (in m) and Q is the discharge (in m3/s). What is the discharge that can now be obtained from the system where the pump is installed at a cross- section of the pipeline?
A 7350 m long, 1050 mm concrete pipeline connects an upstream reservoir (water
surface elevation 433.3 m) to a downstream reservoir (water surface elevation 423.1 m). A
discharge valve at the downstream end is used to control flow; when this valve is fully open,
the measured discharge in the pipeline is 920 L/s under the naturally available head difference.
(a) Assuming fully developed turbulent flow and that all other local losses are negligible,
estimate the loss coefficient k for the fully open valve (assume f = 0.015).
(b) Because of increasing urban development, the flow under the natural head difference is
considered to be inadequate and it is proposed to increase this flow with pumping. The head-
capacity curve for the pump can be approximated by the equation H = 8 – 3.5Q2 in which H is
the total dynamic head on the pump (in m) and Q is the discharge (in m3/s). What is the
discharge that can now be obtained from the system where the pump is installed at a cross-
section of the pipeline?
Step by step
Solved in 3 steps
