- Weber number
The Weber number is a
dimensionless number influid mechanics that is often useful in analysing fluid flows where there is an interface between two different fluids, especially formultiphase flow s with strongly curved surfaces. It can be thought of as a measure of the relative importance of the fluid'sinertia compared to itssurface tension . The quantity is useful in analyzing thin film flows and the formation of droplets and bubbles.It is named after
Moritz Weber (1871 –1951 ) and may be written as::mathit{We} = frac{ ho v^2 l}{sigma}where
* ho is thedensity of the fluid.
* v is itsvelocity .
* l is its characteristiclength , typically the droplet diameter.
* sigma is thesurface tension .The modified Weber number,
We^*=frac{We}{48}
equals the ratio of the kinetic energy on impact to the surface energy,
:We^*=frac{E_{kin{E_{surf,
where
:E_{kin}=pi ho l~^3U~^2/24
and
:E_{surf}=2pi l~^2sigma.
References
*Weast, R. Lide, D. Astle, M. Beyer, W. (1989-1990). CRC Handbook of Chemistry and Physics. 70th ed. Boca Raton, Florida: CRC Press, Inc.. F-373,376.
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