# Evaporation-driven Contact Angles in a Pure-vapor Atmosphere : the Effect of Vapor Pressure Non-uniformity

Mathematical Modelling of Natural Phenomena (2012)

- Volume: 7, Issue: 4, page 53-63
- ISSN: 0973-5348

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topRednikov, A.Y., and Colinet, P.. "Evaporation-driven Contact Angles in a Pure-vapor Atmosphere : the Effect of Vapor Pressure Non-uniformity ." Mathematical Modelling of Natural Phenomena 7.4 (2012): 53-63. <http://eudml.org/doc/222309>.

@article{Rednikov2012,

abstract = {A small vicinity of a contact line, with well-defined (micro)scales (henceforth the
“microstructure”), is studied theoretically for a system of a perfectly wetting liquid,
its pure vapor and a superheated flat substrate. At one end, the microstructure terminates
in a non-evaporating microfilm owing to the disjoining-pressure-induced Kelvin effect. At
the other end, for motionless contact lines, it terminates in a constant film slope
(apparent contact angle as seen on a larger scale), the angle being non-vanishing despite
the perfect wetting due to an overall dynamic situation engendered by evaporation. Here we
go one step beyond the standard one-sided model by incorporating the effect of vapor
pressure non-uniformity as caused by a locally intense evaporation flow, treated in the
Stokes approximation. Thereby, the film dynamics is primarily affected through
thermodynamics (shift of the local saturation temperature and evaporation rate), the
direct mechanical impact being rather negligible. The resulting integro-differential
lubrication film equation is solved by handling the newly introduced effect (giving rise
to the “integro” part) as a perturbation. In the ammonia (at 300 K) example dealt with
here, it proves to be rather weak indeed: the contact angle decreases while the integral
evaporation flux increases just by a few percent for a superheat of ~1 K.
However, the numbers grow (roughly linearly) with the superheat.},

author = {Rednikov, A.Y., Colinet, P.},

journal = {Mathematical Modelling of Natural Phenomena},

keywords = {contact angle; evaporation; superheat; pure vapor; thin films; nonlocal effect},

language = {eng},

month = {7},

number = {4},

pages = {53-63},

publisher = {EDP Sciences},

title = {Evaporation-driven Contact Angles in a Pure-vapor Atmosphere : the Effect of Vapor Pressure Non-uniformity },

url = {http://eudml.org/doc/222309},

volume = {7},

year = {2012},

}

TY - JOUR

AU - Rednikov, A.Y.

AU - Colinet, P.

TI - Evaporation-driven Contact Angles in a Pure-vapor Atmosphere : the Effect of Vapor Pressure Non-uniformity

JO - Mathematical Modelling of Natural Phenomena

DA - 2012/7//

PB - EDP Sciences

VL - 7

IS - 4

SP - 53

EP - 63

AB - A small vicinity of a contact line, with well-defined (micro)scales (henceforth the
“microstructure”), is studied theoretically for a system of a perfectly wetting liquid,
its pure vapor and a superheated flat substrate. At one end, the microstructure terminates
in a non-evaporating microfilm owing to the disjoining-pressure-induced Kelvin effect. At
the other end, for motionless contact lines, it terminates in a constant film slope
(apparent contact angle as seen on a larger scale), the angle being non-vanishing despite
the perfect wetting due to an overall dynamic situation engendered by evaporation. Here we
go one step beyond the standard one-sided model by incorporating the effect of vapor
pressure non-uniformity as caused by a locally intense evaporation flow, treated in the
Stokes approximation. Thereby, the film dynamics is primarily affected through
thermodynamics (shift of the local saturation temperature and evaporation rate), the
direct mechanical impact being rather negligible. The resulting integro-differential
lubrication film equation is solved by handling the newly introduced effect (giving rise
to the “integro” part) as a perturbation. In the ammonia (at 300 K) example dealt with
here, it proves to be rather weak indeed: the contact angle decreases while the integral
evaporation flux increases just by a few percent for a superheat of ~1 K.
However, the numbers grow (roughly linearly) with the superheat.

LA - eng

KW - contact angle; evaporation; superheat; pure vapor; thin films; nonlocal effect

UR - http://eudml.org/doc/222309

ER -

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