Ratio of inertial forces to surface tension forces is called the __________ number.

Q. Ratio of inertial forces to surface tension forces is called the __________ number.

1. Euler
2. Froude
3. Mach
4. Weber

Answer: Weber

The Weber number (We) is a dimensionless number in fluid mechanics that is often useful in analyzing 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 [de] (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.

The Weber Number is the ratio between the inertial force and the surface tension force and the Weber number indicates whether the kinetic or the surface tension energy is dominant.