Computational Modelling of Cardiovascular Stenosis

Abstract

Stenosis is a narrowing of an artery. Atherosclerotic plaque deposits are a common abnormality found in major blood arteries that can potentially perturb the flow field. The work reported here describes the flow pattern in the various shape of stenosed artery for knowing the wall shear stress and pressure distribution. A fully developed pulsatile flow through stenotic tubes was considered. A finite volume CFD solver is developed for simulation of blood flow in 50-90% cross-section area reduction of stenosed artery. Carreau-Yasuda model is considered for modelling of blood viscosity. Inlet condition based on Womersley flow is applied at the inlet of the artery and time-varying spatial pressure boundary condition is imposed as the Dirichlet boundary condition at the outlet. The Neumann boundary conditions (zero gradient of velocity in the axial direction at the outlet) were applied for velocity at the outlet. The code was validated against the well-known problem and good agreement was found. Post-validation, the simulating physiological pulsatile flow was presented for the various shape of stenosis. The result shows that close to stenosis, the flow is transient developed and are responsible for developing high wall shear stress on the wall of arteries. The results show that 90% blockage in an artery can be extremely dangerous, causing the flow pattern distribute and become developing (i.e. velocity profile is not parabolic).