Particle Reynold's Number Calculator

Particle Reynolds Number Formula:

\[ RE = \frac{\rho_{liquid} \times V_s \times D}{\mu_{viscosity}} \]

Liquid Density (ρ):

kg/m³

Settling Velocity (Vₛ):

m/s

Diameter (D):

Dynamic Viscosity (μ):

Pa·s

Particle Reynolds Number (RE):

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1. What is Particle Reynolds Number?

The Particle Reynolds number describes the dynamics of fluid flow around a particle, indicating whether the flow is laminar or turbulent. It's a dimensionless quantity that helps characterize the behavior of particles in fluid systems.

2. How Does the Calculator Work?

The calculator uses the Particle Reynolds Number formula:

\[ RE = \frac{\rho_{liquid} \times V_s \times D}{\mu_{viscosity}} \]

Where:

\( \rho_{liquid} \) — Liquid Density (kg/m³)
\( V_s \) — Settling Velocity (m/s)
\( D \) — Diameter (m)
\( \mu_{viscosity} \) — Dynamic Viscosity (Pa·s)

Explanation: The Reynolds number quantifies the ratio of inertial forces to viscous forces in fluid flow around a particle.

3. Importance of Reynolds Number Calculation

Details: Reynolds number is crucial for predicting flow patterns, determining drag coefficients, and understanding particle behavior in various fluid dynamics applications including sedimentation, filtration, and fluidized bed operations.

4. Using the Calculator

Tips: Enter liquid density in kg/m³, settling velocity in m/s, diameter in meters, and dynamic viscosity in Pa·s. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What does a low Reynolds number indicate?
A: Low Reynolds numbers (RE < 1) indicate laminar flow where viscous forces dominate, resulting in smooth, predictable fluid motion around the particle.

Q2: What does a high Reynolds number indicate?
A: High Reynolds numbers (RE > 4000) indicate turbulent flow where inertial forces dominate, resulting in chaotic, unpredictable fluid motion.

Q3: What is the transition range for Reynolds number?
A: The transition from laminar to turbulent flow typically occurs between Reynolds numbers of 1 to 4000, depending on the specific system geometry.

Q4: How does Reynolds number affect drag coefficient?
A: The drag coefficient varies significantly with Reynolds number, with different relationships in the Stokes flow regime (RE < 1), transition regime, and Newton's law regime (RE > 1000).

Q5: What are typical applications of particle Reynolds number?
A: Applications include particle sedimentation studies, filtration system design, fluidized bed operations, and analysis of particle transport in various industrial processes.