Question

Calculate Reynolds number, if a fluid having viscosity of $0.5{\text{Ns/m}}^2$ and density of $450{\text{kg/m}}^3$, flows through a pipe of $20\text{mm}$ diameter with an average velocity of $2.5\text{m/s}$.

• A. $225$
• B. $90$
• C. $45$
• D. $144$

Answer 1

The correct option is C $45$

We know,
Reynolds number $=\frac{\rho vD}{\mu }=\frac{450\times 2.5\times .02}{0.5}=45$