Concept explainers
A water pump is used to pump water from one large reservoir to another large reservoir that is at a higher elevation. The free surfaces of both reservoirs are exposed to atmospheric pressure, as sketched in Fig. P14-35E. The dimensions and minor loss coefficients are provided in the figure. The pump's performance is approximated by the expression
The capacity delivered by the pump.
Answer to Problem 35EP
The capacity delivered by the pump is
Explanation of Solution
Given information:
The shutoff head is
Write the expression for the required head using the energy balance equation.
Here, the initial pressure is
Write the expression for the roughness factor.
Here, the diameter of the pipe is
Write the expression for the minor losses.
Here, the minor loss coefficient at pipe entrance is
Write the expression for the frictional loss head.
Here, the friction factor is
Write the expression for the available head.
Here, the shutoff head is
Write the expression for the capacity.
Substitute
Write the expression for the Reynolds number.
Here, the density of the water is
Write the expression for the friction factor using the Colebrook equation.
Calculation:
Refer to table A-3E Properties of saturated water to obtain the density of water as
Substitute
Substitute
Substitute
Substitute
Since, the required head is equal to the available head that is
Substitute
Substitute
Substitute
Substitute
Substitute
Conclusion:
The capacity delivered by the pump is
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Chapter 14 Solutions
Fluid Mechanics: Fundamentals and Applications
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