Settling Velocity With Respect To Dynamic Viscosity Calculator

Settling Velocity Formula:

\[ V_s = \frac{[g] \times (\rho_p - \rho_{liquid}) \times D_E^2}{18 \times \mu_{viscosity}} \]

Density of Particle (ρp):

kg/m³

Liquid Density (ρliquid):

kg/m³

Effective Particle Diameter (DE):

Dynamic Viscosity (μviscosity):

Pa·s

Settling Velocity (Vs):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Settling Velocity?

Settling velocity refers to the terminal velocity of a particle in still fluid. It is the constant speed that a particle eventually reaches when the resistance of the fluid equals the force of gravity acting on the particle.

2. How Does the Calculator Work?

The calculator uses the Stokes' law formula for settling velocity:

\[ V_s = \frac{[g] \times (\rho_p - \rho_{liquid}) \times D_E^2}{18 \times \mu_{viscosity}} \]

Where:

\( V_s \) — Settling velocity (m/s)
\( [g] \) — Gravitational acceleration (9.80665 m/s²)
\( \rho_p \) — Density of particle (kg/m³)
\( \rho_{liquid} \) — Liquid density (kg/m³)
\( D_E \) — Effective particle diameter (m)
\( \mu_{viscosity} \) — Dynamic viscosity (Pa·s)

Explanation: This formula calculates the terminal velocity at which a spherical particle settles in a viscous fluid under the influence of gravity.

3. Importance of Settling Velocity Calculation

Details: Settling velocity calculations are crucial in various fields including sediment transport studies, water treatment processes, chemical engineering, and environmental science for predicting particle behavior in fluids.

4. Using the Calculator

Tips: Enter all values in appropriate SI units. Particle density and liquid density must be in kg/m³, particle diameter in meters, and dynamic viscosity in Pascal-seconds (Pa·s). All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What are the limitations of this formula?
A: This formula assumes spherical particles, laminar flow conditions (low Reynolds number), and is most accurate for small particles in viscous fluids.

Q2: When is this formula not applicable?
A: For non-spherical particles, high Reynolds numbers (turbulent flow), or when particle concentration is high enough to cause interference between particles.

Q3: What is the typical range of settling velocities?
A: Settling velocities can range from micrometers per second for very fine particles to several centimeters per second for larger particles, depending on fluid properties.

Q4: How does temperature affect settling velocity?
A: Temperature affects fluid density and viscosity, which in turn influence the settling velocity. Warmer temperatures generally decrease viscosity, increasing settling velocity.

Q5: Can this be used for gas-solid systems?
A: Yes, the same principles apply to particles settling in gases, though the density difference is much larger and other factors may need consideration.