Correct Answer - Option 1 : Laminar flow
Reynold Number:
- It is the ratio of inertia force to viscous force.
- It determines the type of fluid flow.
The expression for Reynold's number is given as:
\(Re\ =\ \frac{ρVD}{μ}\)
Where ρ = density of the fluid, V = mean velocity, D = diameter of the pipe, and μ = dynamic viscosity of the fluid.
- The flow is laminar if Reynold number < 2000.
- The flow is turbulent if Reynold number > 4000.
Calculation:
Given:
D = 5 cm = 5 × 10-2 m, V = 8 cm/sec = 0.08 m/sec, μ = 1.6 × 10-2 Pa-sec, ρ = 1000 kg/m3
\(Re\ =\ \frac{ρVD}{μ}\)
\(Re\ =\ \frac{1000\;\times\;0.08\;\times\;5\;\times\;10^{-2}}{1.5\times\;10^{-2}}=266.6\)
The flow is laminar as Reynold number < 2000