Lewis Number Formula |
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\( Le \;=\; \dfrac{ \alpha }{ D_m }\) (Lewis Number) \( \alpha \;=\; Le \cdot D_m \) \( D_m \;=\; \dfrac{ \alpha }{ Le }\) |
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Symbol | English | Metric |
\( Le \) = Lewis number | \(dimensionless\) | \(dimensionless\) |
\( \alpha \) (Greek symbol alpha) = thermal diffusivity | \(ft^2\;/\;sec\) | \(m^2\;/\;s\) |
\( D_m \) = mass diffusivity | \(ft^2\;/\;sec\) | \(m^2\;/\;s\) |
Lewis number, abbreviated as Le, a dimensionless number, is the ratio of thermal diffusivity to mass diffusivity. It is used to characterize fluid flows where there is simultaneous heat and mass transfer. The Lewis number is often used to characterize heat and mass transfer processes, particularly in situations involving simultaneous heat and mass transfer, such as in combustion, chemical reactions, or natural convection. It provides information about the relative importance of thermal and mass diffusion in a system.
Lewis Number Interpretation
The Lewis number is particularly relevant in fields such as combustion, chemical engineering, and atmospheric science, where the interaction between heat and mass transfer plays a significant role. It helps researchers and engineers understand the interplay between diffusion processes and how they affect the overall behavior of fluid flows with coupled heat and mass transfer.