Hazel, A. L. & Heil, M. (2006) Finite-Reynolds-Number Effects in
Steady, Three-Dimensional Airway Reopening.
ASME Journal of Biomechanical Engineering (in print)
Motivated by the physiological problem of pulmonary airway reopening,
we study the steady propagation of an air finger into a buckled elastic
tube, initially filled with viscous fluid. The system is modelled using
geometrically non-linear, Kirchhoff--Love shell theory, coupled to the
free-surface Navier--Stokes equations. The resulting three-dimensional,
fluid-structure-interaction problem is solved numerically by a
fully-coupled finite element method. Our study focuses on the
effects of fluid inertia, which has been neglected in most previous studies.
The importance of inertial forces is characterised by the
ratio of the Reynolds and capillary numbers, Re/Ca, a
material parameter. Fluid inertia has a significant
effect on the system's behaviour, even at relatively small
values of Re/Ca. In particular, compared to
the case of zero Reynolds number, fluid inertia causes a significant
increase in the pressure required to drive the air finger at a given
Page last modified: Feburary 2, 2006
Back to Matthias Heil's home page.