Project ForgeFluid Mechanics
Bernoulli's Equation & Flow
GATE 2017
Medium
For steady flow of a viscous incompressible fluid through a circular pipe of constant diameter, the average velocity in the fully developed region is constant. Which one of the following statements about the average velocity in the developing region is TRUE?
- AIt increases until the flow is fully developed.
- It is constant and is equal to the average velocity in the fully developed region.
- CIt decreases until the flow is fully developed.
- DIt is constant but is always lower than the average velocity in the fully developed region.
Explanation
By conservation of mass, for steady incompressible flow through a constant-area duct, the average velocity at every cross-section must be identical — the velocity profile shape changes as the flow develops, but the average (bulk) velocity does not.
Source: GATE ME 2017 Session 1 (ME-1) (2017)
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