Pulsatile Flow in a Tube with a Moving Constriction

Abstract

A parametric study of pulsatile flow passing through a tube with a moving axisymmetric constriction on the wall was carried out to study the hemodynamics of the oscillating stenosis in the diseased arteries. Two modes of constriction motion were modeled separately in the present study, by imposing a radially-oscillating or axially-oscillating wave on a tube wall subjected to a pulsatile incoming flow. A linear analytical approach and a numerical model (ALE finite element) were developed to study the effect of the constriction motion with mild and large amplitudes, respectively. The results showed that even when the constriction moves in mild amplitude, the fluctuations due to the incoming pulsatile flow are amplified. At large Womersley number (I? = 10), wavy flow pattern with complicated vortices development were observed for both modes of the constriction motion. The effects induced by the constriction motion are less obvious at large Reynolds number, for example Re = 1000, as the flow is dominated by the large convective inertia.