Oscillation Amplitude of a Collapsible Tube Near the Boundaries of Oscillatory Control-Space at Reynolds Numbers Characteristic of Larger Airways

摘要

The flow-induced oscillation of a collapsible tube is a model for the audible vibrations of various respiratory tract structures. Collapsible-tube oscillations can be mapped in a two-dimensional control space of operating points set by relative pressures. Within the oscillatory regions of that control space, frequency and amplitude vary with position. To determine the nature of the dynamical bifurcation at the boundary of oscillatory control space, it is important to know how oscillation amplitude varies near the boundary. We therefore investigated the control-space distribution of oscillation amplitude, in a region where oscillation occurred at the lowest possible Reynolds number. Control-space diagrams were obtained in the region 135