Related Resources: calculators

### Sphericity of Sphere Formulas and Calculator

Sphericity of a Sphere Formulas and Calculator

Sphericity is, naturally, a measure of how spherical an object is. Defined by Wadell in 1932, the sphericity ψ of a particle is the ratio of the surface area of a sphere with the same volume as the given spherical particle to the surface area of the particle.

The sphericity of a nonspherical particle is always less than 1 and a particle that is a perfect sphere has sphericity value of ψ = 1.000 .

Sphericity is a measure of how closely the shape of an object resembles that of a perfect sphere. For example, the sphericity of the balls inside a ball bearing determines the quality of the bearing, such as the load it can bear or the speed at which it can turn without failing. Sphericity of a Sphere can be calculated by the following formula:

Eq :

Ψ = ( π1/3 ( 6 VP )2/3) / Ap

Where:

VP = volume of the particle
Ap = the surface area of the particle
A particle that is a perfect sphere has sphericity value of ψ = 1.)

Reference:

Machinery's Handbook 30th edition

Related: 