Question

For the flow through a pipe, if Reynolds's number is greater than 4000, it indicates:

• A. Streamline flow
• B. Laminar flow
• C. Steady flow
• D. Turbulent flow

Hint:

Reynolds's number is crucial in determining the flow regime. A high Reynolds number typically indicates turbulent flow, while a low number indicates laminar flow.

Answer 1

The Correct Option is D

Step 1: Understanding Reynolds's Number.
Reynolds's number (\( Re \)) is a dimensionless quantity that helps predict the flow regime of a flui(D) It is defined as: \[ Re = \frac{\rho v D}{\mu} \] Where: \( \rho \) = density of the fluid \( v \) = velocity of the fluid \( D \) = characteristic length (diameter of the pipe) \( \mu \) = dynamic viscosity of the fluid
Step 2: Flow Regimes.
- \( Re<2000 \): Laminar flow (smooth and orderly) - \( Re>4000 \): Turbulent flow (chaotic and irregular) - \( 2000<Re<4000 \): Transitional flow (can shift between laminar and turbulent)
Step 3: Conclusion.
If Reynolds's number is greater than 4000, it indicates turbulent flow. Therefore, the correct answer is (D).