Laplace number explained

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:^[1]

$\backslash mathrm\; =\; \backslash mathrm\; =\; \backslash frac$

where:

• σ = surface tension
• ρ = density
• L = length
• μ = liquid viscosity

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

La = (Re ^{2})/(We)

See also

• Ohnesorge number - There is an inverse relationship,

La = Oh ^{-2} , between the Laplace number and the Ohnesorge number.

Notes and References

1. Balakotaiah . V. . Jayawardena . S. S. . Nguyen . L. T. . Studies on Normal and Microgravity Annular Two Phase Flows . Proceedings of the Fourth Microgravity Fluid Physics and Transport Phenomena Conference . 1999 . 27 May 2024.