Lewis Number

Compare thermal diffusivity against mass diffusivity.

visual calculatorHeat Transfer

Read the flow shape before trusting the number.

This page turns a CFD setup into regime, scale, and dominant-effect cues. Adjust the calculator below and compare the moving graphic with the computed result.

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Lewiscombustionmass transfer

formula

KaTeX rendered

\begin{aligned}\text{Le = alpha / D = Sc / Pr}\end{aligned}

ASCII source

Le = alpha / D = Sc / Pr

thermal diffusivity alpha (m^2/s)mass diffusivity D (m^2/s)

1.1000

interpretation

comparable diffusion rates

Lewis number matters in combustion and reactive mixing, where thermal and species layers may separate in thickness.

Lewis combustion mass transfer