Home › Previous year questions › GATE 2022 PI › Question 27GATE 2022 PI – Question 27 General Engineering · Thermal and Fluids Engineering · 1 mark · Numerical answer
Water of kinematic viscosity 1 × 10⁻⁶ m²/s flows through an 8 mm horizontal circular pipe. Flow is fully developed and laminar, with maximum axial velocity 0.5 m/s. Find Reynolds number, nearest integer.
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Show answer and explanation Correct answer: 1995 to 2005
Explanation Laminar circular-pipe velocity is parabolic, with mean speed half the maximum: 0.25 m/s. Therefore $Re=\bar uD/\nu=0.25(0.008)/10^{-6}=\mathbf{2000}$.
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