<P> The Weber number (We) is a dimensionless number in fluid mechanics that is often useful in analysing fluid flows where there is an interface between two different fluids, especially for multiphase flows with strongly curved surfaces . It is named after Moritz Weber (1871--1951). It can be thought of as a measure of the relative importance of the fluid's inertia compared to its surface tension . The quantity is useful in analyzing thin film flows and the formation of droplets and bubbles . </P> <P> The Weber number may be written as: </P>

Ratio of inertial force to surface tension is known as