# Weber Number

Written by Jerry Ratzlaff on . Posted in Dimensionless Numbers

## Weber Number

Weber number ( $$We$$ ) (dimensionless number) in fluid mechanics is often useful in analysing fluid flows where there is an interface between two different fluids, especially for multiphase flows with strongly curved surfaces.

### Weber Number FORMULA

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

Where:

$$\large{ We }$$ = Weber number

$$\large{ \rho }$$  (Greek symbol rho) = mass density

$$\large{ v }$$ = velocity

$$\large{ l }$$ = characteristic length

$$\large{ \sigma }$$  (Greek symbol sigma) = surface tension

Solve for:

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

$$\large{ v = \sqrt { \frac { We \sigma } { \rho l } } }$$

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

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

Tags: Equations for Flow