Capillary number
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In fluid dynamics, the capillary number represents the relative effect of viscous forces versus surface tension acting across an interface between a liquid and a gas, or between two immiscible liquids. It is defined as
where μ is the viscosity of the liquid, v is a characteristic velocity and σ is the surface or interfacial tension between the two fluid phases.
For low capillary numbers (a rule of thumb says less than 10 - 5), flow in porous media is dominated by capillary forces.
[edit] See also
Dimensionless numbers in fluid dynamics |
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Archimedes • Bagnold • Bond • Brinkman • Capillary • Damköhler • Deborah • Eckert • Ekman • Euler • Froude • Galilei • Grashof • Hagen • Knudsen • Laplace • Lewis • Mach • Marangoni • Nusselt • Ohnesorge • Péclet • Prandtl • Rayleigh • Reynolds • Richardson • Rossby • Schmidt • Sherwood • Stanton • Stokes • Strouhal • Weber • Weissenberg • Womersley |