Instability in three-dimensional, unsteady, stenotic flows

The paper presents a computational investigation of instabilities in pulsatile flow through a three-dimensional stenosis. The computations have been conducted using a third-order high-resolution scheme and a non-linear multigrid algorithm. The simulations reveal the existence of unstable flow throughout the pulsatile cycle. The instability is manifested by asymmetric flow patterns though the stenosis is axisymmetric-large flow variations in the cross-sectional planes, and swirling motion in the poststenotic region. The instability leads to a strongly disturbed flow several radii downstream of the stenosis, as well as spatiotemporal fluctuations of the circumferential shear stress and vorticity. (C) 2002 Elsevier Science Inc. All rights reserved.