Lewis number
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can be expressed as | can be expressed as | ||
:<math> | :<math> | ||
- | Le_k | + | Le_k \equiv \frac{D_{th}}{ D_k} |
</math> | </math> | ||
which is the ratio of the heat diffusion speed to the diffusion speed of species <math> k </math>. | which is the ratio of the heat diffusion speed to the diffusion speed of species <math> k </math>. | ||
In many combustion models, all species are assumed to diffuse at the same speed and therefore | In many combustion models, all species are assumed to diffuse at the same speed and therefore | ||
- | <math> Le | + | <math> Le = 1 </math> |
[[Category:Dimensionless parameters]] | [[Category:Dimensionless parameters]] |
Latest revision as of 09:55, 17 December 2008
The Lewis number for a given species is
Denoting the heat diffusivity coefficient the Lewis number can be expressed as
which is the ratio of the heat diffusion speed to the diffusion speed of species .
In many combustion models, all species are assumed to diffuse at the same speed and therefore