Liquid Bridges in Non-Axisymmetrically Buckled Elastic
Detailed computational parameter studies lead to the following
- For sufficiently large surface tensions, the compressive load
exerted by the liquid bridge on the tube wall is strong enough
to make it buckle non-axisymmetrically.
- For many combinations of the control parameters (external pressure
and surface tension) multiple buckled equilibrium configurations exist.
- Many of these equilibrium configurations are statically unstable.
If perturbed slightly, the system would collapse into an even more strongly
- For physiologically realistic parameter values [given by Halpern &
Grotberg: `Fluid-Elastic Instabilities of Liquid-Lined Flexible
tubes.' Journal of Fluid Mechanics 244, 615-632 (1992)], we predict
the airway walls to collapse very strongly.
- The fluid volume required to form an occluding liquid bridge in
a non-axisymmetrically buckled tube can be as low as 10% of the
minimal liquid bridge volume in an axisymmetric tube.
- For sufficiently high surface tension buckling takes place
in multiple modes (as observed physiologically) and the loss
of stability of the axisymmetric configuration is followed
by a `catastrophic' collapse into a strongly deformed configuration
with opposite wall contact in which the fluid contained in the initial
axisymmetric liquid bridge gets spread out along the tube.
Page last modified: September 29, 2000
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