Sommerfield Number

Written by Jerry Ratzlaff on . Posted in Dimensionless Numbers

Sommerfield number, abbreviated as S, a dimensionless number, is used extensively in hydrodynamic lubrication analysis.

Sommerfield Number Formula

\(\large{ S = \left( \frac{ r }{ c } \right)^2 \; \frac{ \mu\;n}{P}  }\)

Where:

\(\large{ S }\) = Sommerfield number

\(\large{ \mu }\)  (Greek symbol mu) = absolute viscosity

\(\large{ P }\) = load per unit of projected bearing area

\(\large{ c }\) = radius clearance

\(\large{ r }\) = shaft radius

\(\large{ n }\) = shaft rotational speed

 

Tags: Equations for Fluid