Pulsatile flow through a constricted tube: effect of stenosis morphology on hemodynamic parameters

In this paper, we investigate pulsatile flow through a constricted tube with the aim of assessing the effect of stenosis morphology on hemodynamic parameters. The fluid-solid interaction of pulsatile flow through a compliant tube with elastic walls was simulated using an arbitrary Lagrangian-Eulerian (ALE) finite-element method. We consider blood flow through various mild stenoses of 25.8% severity in diameter with trapezoidal and bell-like morphologies at a fixed Womersley number of 7.75. The results show that the distribution of the time-averaged wall shear stress (TAWSS), which is the main factor affecting the hemodynamic parameters, strongly depends on the axial stretch of the stenosis; elongation of the stenotic region increases by 41.1% the maximum TAWSS for stenoses of trapezoidal morphology whereas the maximum TAWSS decreases by 14.8% for the corresponding stenoses of bell-like morphology. The present findings indicate that risk factors due to atherosclerosis may vary in a complicated manner as an atheromatous plaque gradually builds up and morphs with time.