Capillary action is the ability of a liquid to flow in narrow spaces without external forces like gravity. It is sometimes called capillarity or wicking. Capillary action draws liquids up between hairs, drains tears from the eyes, draws ink to fountain pen tips, and moves groundwater. There are two types: capillarity rise, where liquids rise in small diameter tubes against gravity, and capillarity fall, where liquids are depressed. Examples of capillary action include the absorption of ink by blotting paper and the rise of oil in a lamp wick. Supply of water to tall tree leaves is also through capillary rise.
Surface Tension
Surface Tension in Detail
Surface Tension on Liquid Droplet
Surface Tension on Hollow Droplet
Surface Tension on Liquid Jet
Capillary
Expression for Capillary Rise
Expression for Capillary Fall
Sources
Reynolds number and geometry concept, Momentum integral equations, Boundary layer equations, Flow over a flat plate, Flow over cylinder, Pipe flow, fully developed laminar pipe flow, turbulent pipe flow, Losses in pipe flow
Surface Tension
Surface Tension in Detail
Surface Tension on Liquid Droplet
Surface Tension on Hollow Droplet
Surface Tension on Liquid Jet
Capillary
Expression for Capillary Rise
Expression for Capillary Fall
Sources
Reynolds number and geometry concept, Momentum integral equations, Boundary layer equations, Flow over a flat plate, Flow over cylinder, Pipe flow, fully developed laminar pipe flow, turbulent pipe flow, Losses in pipe flow
A fluid is a state of matter in which its molecules move freely and do not bear a constant relationship in space to other molecules.
In physics, fluid flow has all kinds of aspects: steady or unsteady, compressible or incompressible, viscous or non-viscous, and rotational or irrotational to name a few. Some of these characteristics reflect properties of the liquid itself, and others focus on how the fluid is moving.
Fluids are :-
Liquid : blood, i.v. infusions)
Gas : O2 , N2O)
Vapour (transition from liquid to gas) : N2O (under compression in cylinder), volatile inhalational agents (halothane, isoflurane, etc)
Sublimate (transition from solid to gas bypassing liquid state) : Dry ice (solid CO2), iodine
2. Ability of a liquid to flow in narrow spaces without the
assistance of, and in opposition to, external forces like gravity
Capillary action is sometimes called capillarity, capillary
motion, or wicking
3. Drawing up of liquids between the hairs of a paint-brush
Drainage of constantly produced tear fluid from the eye
Observed in thin layer chromatography
draws ink to the tips of fountain pen nibs
moving groundwater from wet areas of the soil to dry areas
5. Tendency of liquids to rise in tubes of small diameter in
opposition to, external forces like gravity
6. Tendency of liquids to be depressed in tubes of small
diameter in opposition to, external forces like gravity
7. Lubricating oil spread easily on all parts because of their low
surface tension.
Cotton dresses are preferred in summer because cotton dresses
have fine pores which act as capillaries for sweat.
Dirt get removed when detergents are added while washing
clothes because surface tension of water is reduced.
8. The absorption of ink by a blotting paper is due to
capillary action, as the blotting paper is porous. When
it is placed over the ink, the ink raises into the pores.
Also rise of oil in the wick of a lamp is due to capillary
action.
If one end of a towel is dipped into a bucket of water
and the other end hangs over the bucket, the entire
towel soon becomes wet due to capillary action.
Supply of water to the leaves at the top of even a tall
tree is through capillary rise.
9. A fabric can be waterproof, by adding suitable
waterproofing materials to the fabric. This addition
increases the angle of contact, thereby making the
fabric waterproof.
