Enter the density of the solids, density of the fluid, diameter of the solids, and kinematic viscosity into the calculator to determine the settling velocity.

Settling Velocity Formula

The following equation is used to calculate the Settling Velocity.

V = g*(ps/pf-1)*d^2 / 18*v
  • Where V is the settling velocity
  • g is the acceleration due to gravity (9.81 m/s^2)
  • ps is the density of the solid (kg/m^3)
  • pf if the density of the fluid (kg/m^3)
  • d is the diameter of the solid (m)
  • v is the kinematic viscosity

What is a Settling Velocity?

Settling velocity refers to the speed at which particles or objects in a fluid, such as water or air, fall or drop due to the force of gravity. It is a critical parameter used to understand and analyze the behavior of particles in various natural and engineered systems.

Understanding settling velocity is important for several reasons.

It helps in predicting the behavior of sediment particles in rivers, lakes, and oceans. Studying settling velocity, scientists and engineers can estimate the movement and deposition of sediments, which is crucial for managing water resources, maintaining navigation channels, and protecting ecosystems.

Settling velocity is also significant in wastewater treatment processes. In wastewater treatment plants, particles and solids must be separated from the liquid phase. Settling velocity helps determine the efficiency of sedimentation tanks and clarifiers, which are used for solid-liquid separation.

How to Calculate Settling Velocity?

Example Problem:

The following example outlines the steps and information needed to calculate the Settling Velocity.

First, determine the density of the solid. In this example, the density of the solid is found to be 600 kg/m^3.

Next, determine the density of the fluid. For this problem, the density of the fluid is found to be 1.225 kg/m^3.

Next, determine the diameter of the solid. In this case, the diameter of the solid is measured to be .0015.

Next, determine the kinematic viscosity. This is calculated to be .46.

Finally, calculate the Settling Velocity using the formula above:

V = g*(ps/pf-1)*d^2 / 18*v

V = 9.81*(600/1.225-1)*.0015^2 / (18*.46)

V = 0.00130301303