Two pipes of identical length with diameters d and 2d are linked in series. What is the diameter of an equivalent single pipe of the same length________________?
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Answer: A. less than d
Explanation
Connecting two pipes in series with diameters d and 2d results in an equivalent single pipe diameter less than d. Head losses are heavily dominated by the smaller diameter pipe due to its high flow resistance. Hydraulic equivalence calculations confirm that the smaller pipe restricts overall capacity significantly. Pipes in series carry the exact same volumetric discharge rate through sequential sections. Frictional head loss varies inversely with the fifth power of the pipe diameter in Darcy-Weisbach equations. Equivalent pipes produce the same total head loss for the given discharge as the combined system.
Municipal water engineers evaluate series pipe networks when upgrading aging urban distribution lines. Ignoring bottleneck pipe diameters leads to severe underestimations of system pressure drops. Proper equivalent sizing ensures booster pumps can overcome cumulative system resistance. Saying the equivalent diameter is between d and 1.5d overestimates the choking effect of the smaller pipe. Diameters between 1.5d and 2d incorrectly neglect the dominant head loss caused by the smaller section. Diameters greater than 2d defy basic continuity and friction loss principles for series pipes.
- Subject
- Engineering
- Category
- Civil Engineering
- Topic
- —
- Difficulty
- medium
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