1. What is Reynolds Number?

The Reynolds number is the ratio of inertial forces to viscous forces within a fluid which is subjected to relative internal movement due to different fluid velocities. A region where these forces change behavior is known as a boundary layer, such as the bounding surface in the interior of a pipe.

2. How Does the Calculator Work?

The calculator uses the Reynolds Number formula:

Where:

• \( \Delta m \) — Mass Flux (kg/s·m²)
• \( D_e \) — Equivalent Diameter (m)
• \( \mu \) — Viscosity of Fluid (Pa·s)

Explanation: The Reynolds number helps predict flow patterns in different fluid flow situations by comparing inertial forces to viscous forces.

3. Importance of Reynolds Number

Details: Reynolds number is crucial for determining whether a fluid flow is laminar or turbulent, which affects heat transfer rates, pressure drops, and overall system performance in heat exchangers and other fluid systems.

4. Using the Calculator

Tips: Enter mass flux in kg/s·m², equivalent diameter in meters, and viscosity in Pa·s. All values must be positive and non-zero.

5. Frequently Asked Questions (FAQ)

Q1: What does Reynolds number indicate?
A: Reynolds number indicates the flow regime - laminar (Re < 2300), transitional (2300 < Re < 4000), or turbulent (Re > 4000) flow.

Q2: Why is Reynolds number important in heat exchangers?
A: It helps determine heat transfer coefficients, pressure drops, and optimal design parameters for efficient heat exchange.

Q3: What is mass flux?
A: Mass flux is the rate of mass flow per unit area, typically measured in kg/s·m².

Q4: What is equivalent diameter?
A: Equivalent diameter is the diameter equivalent to the given value, used for non-circular ducts and channels.

Q5: How does viscosity affect Reynolds number?
A: Higher viscosity decreases Reynolds number, making flow more likely to be laminar, while lower viscosity increases Reynolds number, promoting turbulent flow.