Instabilities of flows through deformable tubes and channels
Oliver Jensen (University of Nottingham)
Thursday 6th November, 2008 14:00-15:00 Mathematics Building, 204
The motion of air and other liquids in lung airways, or blood in veins and arteries, can be strongly influenced by interactions between hydrodynamic forces and elastic (and sometimes muscular) forces in the vessel wall. These interactions generate a variety of instabilities, including familiar examples such as wheezing and flow limitation in asthma. Theoretical models and experiments have shown how single-phase flow, driven through a segment of flexible tube, is subject to distinct modes of self-excited oscillation spanning a wide range of frequencies. I will explain how a high frequency mode can be captured via rigorous high-Reynolds-number asymptotics, supported by computation, allowing the global energy budget to be tracked and revealing connections with underlying local modes and the critical role of boundary conditions. I will also explain how simplified models capture the overall dynamics of this system.