Settling Velocity With Respect To Kinematic Viscosity Calculator

Settling Velocity Formula:

\[ V_s = \frac{[g] \times (SG - G_f) \times D^2}{18 \times \nu} \]

Specific Gravity of Material (SG):

Specific Gravity of Fluid (Gf):

Diameter (D):

Kinematic Viscosity (ν):

m²/s

Settling Velocity (Vs):

m/s

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1. What is Settling Velocity?

Settling velocity refers to the terminal velocity of a particle in still fluid. It's 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:

\[ V_s = \frac{[g] \times (SG - G_f) \times D^2}{18 \times \nu} \]

Where:

\( V_s \) — Settling velocity (m/s)
\( [g] \) — Gravitational acceleration (9.80665 m/s²)
\( SG \) — Specific gravity of material
\( G_f \) — Specific gravity of fluid
\( D \) — Diameter of particle (m)
\( \nu \) — Kinematic viscosity of fluid (m²/s)

Explanation: This formula calculates the terminal velocity of spherical particles settling in a viscous fluid under gravity, assuming laminar flow conditions.

3. Importance of Settling Velocity Calculation

Details: Settling velocity calculations are crucial in various engineering applications including sedimentation processes, water treatment, mineral processing, and environmental studies of particle transport in fluids.

4. Using the Calculator

Tips: Enter specific gravity values (dimensionless), diameter in meters, and kinematic viscosity in m²/s. All values must be positive and valid for accurate results.

5. Frequently Asked Questions (FAQ)

Q1: What are the limitations of this formula?
A: This formula assumes spherical particles, laminar flow conditions (Re < 0.3), and is valid for small particles in viscous fluids.

Q2: How does temperature affect settling velocity?
A: Temperature affects kinematic viscosity, which inversely affects settling velocity. Higher temperature typically means lower viscosity and higher settling velocity.

Q3: What is the range of validity for this equation?
A: The equation is valid for Reynolds numbers less than 0.3, which typically corresponds to small particles (usually < 100 μm) in viscous fluids.

Q4: How does particle shape affect settling velocity?
A: Non-spherical particles have different drag coefficients and typically settle slower than spherical particles of equivalent volume.

Q5: Can this be used for air as the fluid?
A: While the formula is theoretically applicable, air's low viscosity means it's rarely in the laminar flow regime needed for Stokes' law to be accurate.