Lewis Number Calculator

Formula

The formula to calculate the Lewis Number (Le) is:

\[ Le = \frac{a}{Dc} \]

Where:

\( Le \) is the Lewis Number
\( a \) is the thermal diffusivity (m²/s)
\( Dc \) is the mass diffusivity (m²/s)

What is the Lewis Number?

The Lewis Number (Le) is a dimensionless number that characterizes the ratio of thermal diffusivity to mass diffusivity. It is used in heat and mass transfer processes to describe the relative rates of thermal and mass diffusion.

Example Calculation

Let's consider an example:

Thermal Diffusivity (a): 0.01 m²/s
Mass Diffusivity (Dc): 0.005 m²/s

Using the formula to calculate the Lewis Number:

\[ Le = \frac{0.01}{0.005} = 2 \]

This means that the Lewis Number is 2.