- Capillary length
In
fluid mechanics , capillary length is a characteristic length scale for fluid subject to a body force fromgravity and a surface force due tosurface tension .The capillary length is defined asG.K. Batchelor, 'An Introduction To Fluid Dynamics', Cambridge University Press (1967)] ::lambda_{c} = sqrt{frac{gamma}{ ho g,
where g is the acceleration due to gravity and ho is the density of the fluid, and gamma is the
surface tension of the fluid-fluid interface.For clean water at standard temperature and pressure, the capillary length is ~2mm.
A
capillary surface that has a characteristic length smaller than the capillary length can be considered a lowBond number surface. Asessile drop whose largest dimension is smaller than the capillary length, for example, will take the shape ofspherical cap , which is the solution to theYoung-Laplace equation with gravity completely absent.ee also
*
Surface tension
*Young-Laplace equation
*Capillarity References
Wikimedia Foundation. 2010.