In the design of fluid bearings, the Sommerfeld number (S) is a dimensionless quantity used extensively in hydrodynamic lubrication analysis. The Sommerfeld number is very important in lubrication analysis because it contains all the variables normally specified by the designer.
The Sommerfeld number is named after Arnold Sommerfeld (1868–1951).
Definition
The Sommerfeld Number is typically defined by the following equation.
Derivation
Petroff’s Law
