A space–time analysis of blood flow in a 3D vessel with multiple aneurysms

摘要

In this study, 3D unsteady flow dynamics in an arterial vessel with two asymmetric aneurysms in series have been numerically investigated under pulsatile flow conditions for a full cycle of period T. The non-linear partial differential equations governing the conservation of mass and momentum of viscous incompressible fluid have been numerically analysed by a time accurate cell centered finite volume method in implicit Euler time marching setting. The influence of Reynolds' number (Re), Strouhal's number (St), and degree of dilations (δ1 1, δ2 1, δ1 2, δ2 2) on wall shear stress (WSS), wall pressure (WP) and velocities (u, v, w) have been investigated. While the WSSs increase with either increasing St or increasing Re, WPs are seen to get lowered. During the systolic phase high WPs are seen at the distal end of aneurysms, especially at the distal tip of the larger aneurysm. Decreasing St is seen to delay the flow separation process but the vortex shedding with 3D features is always noticed towards the end of the diastolic phase of the flow cycle.