Project ForgeFluid Mechanics
Bernoulli's Equation & Flow
GATE 2019
Medium
Water enters a circular pipe of length L=5.0 m and diameter D=0.20 m with Reynolds number ReD=500. The velocity profile at the inlet of the pipe is uniform while it is parabolic at the exit. The Reynolds number at the exit of the pipe is ___.
500(± 1 accepted)
Explanation
Reynolds number is defined using the average (bulk) velocity, pipe diameter, and fluid properties — none of which change along the pipe for incompressible flow, regardless of how the velocity PROFILE shape develops from uniform to parabolic. So ReD at the exit is unchanged: 500.
Source: GATE ME 2019 Session 2 (Set 3) (2019)
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