# Bejan Number - Mass Transfer

Written by Jerry Ratzlaff on . Posted in Dimensionless Numbers

Bejan number - mass transfer, abbreviated as Be, a dimensionless number, is the pressure drop along a channel of length.

### Bejan Number - Mass Transfer Formula

$$\large{ Be = \frac{ \Delta p \; l^2 }{ \mu \; D_m } }$$

Where:

$$\large{ Be }$$ = Bejan number

$$\large{ l }$$ = channel of length

$$\large{ D_m }$$ = mass diffusivity

$$\large{ \mu }$$  (Greek symbol mu) = dynamic viscosity

$$\large{ \Delta p }$$ = pressure drop