1. What is Reynolds Number?

Reynolds Number is a dimensionless quantity used in fluid mechanics to predict flow patterns in different fluid flow situations. It represents the ratio of inertial forces to viscous forces within a fluid.

2. How Does the Calculator Work?

The calculator uses the Reynolds Number formula:

Where:

• \( d \) — Diameter of Circular Duct (m)
• \( V_m \) — Mean Velocity of Air (m/s)
• \( \upsilon \) — Kinematic Viscosity (m²/s)

Explanation: The Reynolds Number helps determine whether a fluid flow is laminar or turbulent. Lower values indicate laminar flow, while higher values indicate turbulent flow.

3. Importance of Reynolds Number

Details: Reynolds Number is crucial for predicting flow behavior, designing fluid systems, and analyzing heat transfer and friction losses in pipes and ducts.

4. Using the Calculator

Tips: Enter the diameter of the circular duct in meters, mean velocity of air in m/s, and kinematic viscosity in m²/s. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the significance of Reynolds Number?
A: Reynolds Number helps predict flow patterns and determine whether flow is laminar, transitional, or turbulent.

Q2: What are typical Reynolds Number ranges?
A: Typically, Re < 2300 indicates laminar flow, 2300 < Re < 4000 indicates transitional flow, and Re > 4000 indicates turbulent flow.

Q3: Why is kinematic viscosity used instead of dynamic viscosity?
A: Kinematic viscosity (ν) is dynamic viscosity (μ) divided by density (ρ), making it more convenient for flow calculations where density varies.

Q4: Can this calculator be used for liquids as well?
A: Yes, the Reynolds Number formula applies to both gases and liquids, as long as the appropriate viscosity value is used.

Q5: What factors affect Reynolds Number?
A: Reynolds Number is affected by fluid velocity, characteristic length (diameter), and fluid properties (viscosity and density).