Landau-Levich-Derjaguin picture

Landau-Levich-Derjaguin picture

[¦lan‚dȧu̇ ¦lev·ich ′der·zhə‚gēn ‚pik·chər]
(fluid mechanics)
A theory of fluid coating at low velocities, according to which the thickness of the film that forms when a solid is drawn out of a bath results from a balance between (1) the effects of viscosity, which causes a macroscopic entrainment of liquid by the solid, and (2) surface tension, which resists the film entrainment, so that the film thickness is proportional to the capillary number raised to the 2/3 power.