Capillary waves: Difference between revisions

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(Thermal) capillary waves are oscillations of an [[interface]]
(Thermal) '''capillary waves''' are oscillations of an [[interface]]
which have a thermal origin (there are also capillary waves that
which are thermal in origin (there are also capillary waves that
are ordinary waves excited in an interface, such as ripples in
are ordinary waves excited in an interface, such as ripples on
a water surface.)
a water surface.)


Line 7: Line 7:
fluctuations distort an interface. It starts from some '''intrinsic surface'''
fluctuations distort an interface. It starts from some '''intrinsic surface'''
that is distorted. A well-known prediction is that
that is distorted. A well-known prediction is that
the width of the interface is bound to diverge with its area. On the
the width of the interface is bound to diverge with its area. However, this divergence is extremely weak, and is damped
other hand ,this divergence is extremely weak, and is damped
by the presence of an external field. For example, the action
by the presence of an external field. For example, the action
of gravity is sufficient to keep the width fluctuation on the order
of gravity is sufficient to keep the width fluctuation on the order
of one molecular diameter for areas about 1mm<math>^2</math> (Ref. 1).
of one molecular diameter for areas of about 1mm<math>^2</math> (Ref. 1).


Recently, a procedure has been proposed to obtain a molecular intrinsic
Recently, a procedure has been proposed to obtain a molecular intrinsic
surface from simulation data (Ref. 2). The density profiles obtained
surface from simulation data (Ref. 2). The density profiles obtained
from this surface are, in general, quite different from the usual
from this surface are, in general, quite different from the usual
ones (the ''mean density profiles''.)
''mean density profiles''.


==References==
==References==
# J. S. Rowlinson and B. Widom "Molecular Theory of Capillarity". Dover 2002 (originally: Oxford University Press 1982)
# J. S. Rowlinson and B. Widom "Molecular Theory of Capillarity". Dover 2002 (originally: Oxford University Press 1982)
#[http://dx.doi.org/10.1103/PhysRevLett.91.166103 Chacón E, Tarazona P "Intrinsic profiles beyond the capillary wave theory: A Monte Carlo study", Physical Review Letters '''91''' p. 166103 (2003)]
#[http://dx.doi.org/10.1103/PhysRevLett.91.166103 E. Chacón and P. Tarazona "Intrinsic profiles beyond the capillary wave theory: A Monte Carlo study", Physical Review Letters '''91''' 166103 (2003)]
[[Category: Non-equilibrium thermodynamics]]
[[Category: Non-equilibrium thermodynamics]]

Revision as of 13:33, 5 November 2007

(Thermal) capillary waves are oscillations of an interface which are thermal in origin (there are also capillary waves that are ordinary waves excited in an interface, such as ripples on a water surface.)

Capillary wave theory (CWT) is a classic account of how thermal fluctuations distort an interface. It starts from some intrinsic surface that is distorted. A well-known prediction is that the width of the interface is bound to diverge with its area. However, this divergence is extremely weak, and is damped by the presence of an external field. For example, the action of gravity is sufficient to keep the width fluctuation on the order of one molecular diameter for areas of about 1mm (Ref. 1).

Recently, a procedure has been proposed to obtain a molecular intrinsic surface from simulation data (Ref. 2). The density profiles obtained from this surface are, in general, quite different from the usual mean density profiles.

References

  1. J. S. Rowlinson and B. Widom "Molecular Theory of Capillarity". Dover 2002 (originally: Oxford University Press 1982)
  2. E. Chacón and P. Tarazona "Intrinsic profiles beyond the capillary wave theory: A Monte Carlo study", Physical Review Letters 91 166103 (2003)