Liquid Bridges in Non-Axisymmetrically Buckled Elastic
Tubes:
Results for Zero Surface Tension
If the surface tension is negligible then there is no pressure jump
over the meniscus: the wall is compressed by the spatially
constant external pressure. When this external pressure exceeds a
critical value, the tube buckles non-axisymmetrically but its
cross-section is the same throughout
its length. The axial position of the liquid bridge in a uniformly
collapsed tube is arbitrary.
For the example shown below, it was
fixed by keeping the apex of the meniscus attached to `end' of
the tube at z=0.
The figure above shows a sequence of increasingly strongly collapsed
tubes, containing a single meniscus.
The meniscus shape is completely determined by the wall shape and the
contact angle (10o for the example shown). Note how a long thin `meniscus finger'
develops along the tube's centreline as the tube's collapse
increases. The development of this
meniscus finger is closely related to the fact that the meniscus is
a surface of constant mean curvature.
Back to
`Airway Closure'.
Page last modified: February, 23 1998
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