Laplace number

The Laplace number (La), also known as the Suratman number (Su), is a dimensionless number used in the characterization of free surface fluid dynamics. It represents a ratio of surface tension to the momentum-transport (especially dissipation) inside a fluid.

It is defined as follows:

La = Su = \frac{\sigma \rho L}{\mu^2}\,

where:

Laplace number is related to Reynolds number (Re) and Weber number (We) in the following way:

La = \frac{Re^2}{We}\,

See also