Weber Number

Reference data and engineering information about weber number for fluid mechanics applications.

webernumberCalculator

Overview

The Weber number ( $We$ ) is a dimensionless number comparing inertial forces to surface tension forces. It is important in droplet formation, bubble dynamics, and free surface flows.

Variables

Symbol	Description	Unit
$We$	Weber number	—
$\rho$	Fluid density	kg/m³
$v$	Flow velocity	m/s
$L$	Characteristic length	m
$\sigma$	Surface tension	N/m

Formula

$We = \frac{\rho v^2 L}{\sigma}$

Calculator

Notes

Results are approximate and should be verified for critical applications
Input values should be within reasonable engineering ranges

Formula

The Weber number is expressed as:

$We = \frac{\rho v^2 l}{\sigma}$

Applications

The Weber number is useful for analyzing flows where surface tension effects are significant. Its value indicates the relative importance of inertial forces versus surface tension forces.

Droplet and Bubble Formation: Helps predict whether a liquid jet will break up into droplets.
Thin Film Flows: Analyzes the stability and breakup of liquid films.
Multiphase Flows: Characterizes the behavior of interfaces between different fluids, such as in atomization and spray processes.

References

Original Source

Source: engineeringtoolbox.com