Pulsatile Non-Newtonian Fluid Flows in a Model Aneurysm with Oscillating Wall

Abstract

This research presents a numerical simulation of an unsteady two-dimensional channel flow of Newtonian and some non-Newtonian fluids using the finite-volume method. The walls of the geometry oscillate sinusoidally with time. We have used the Cartesian curvilinear coordinates to handle complex geometries, i.e., arterial stents and bulges and the governing Navier-Stokes equations have been modified accordingly. Physiological pulsatile flow has been used at the inlet to characterize four different non-Newtonian models, i.e., the (i) Carreau, (ii) Cross, (iii) Modified Casson, and (iv) Quemada. We have presented the numerical results in terms of wall shear stress (WSS), pressure distribution as well as the streamlines and discussed the hemodynamic behaviors for laminar and laminar to turbulent transitional flow conditions. An increase of wall shear stress and a decrease in wall pressure are significantly observed at the stenosis throat for high Reynolds number and highly stenosed arteries. Likewise, the flow recirculation also increases if the narrowing level and the Reynolds number increases in the dilated region which eventually leads the stream to experience a transition to turbulence at Re = 750. The results for the fluid flow through an aneurysm just after a stenosis with oscillating wall are novel in the literature.

A Graphics Process Unit-Based Multiple-Relaxation-Time Lattice Boltzmann Simulation of Non-Newtonian Fluid Flows in a Backward Facing Step

“…Recently, several studies based on the finite difference and finite volume methods for the Naiver-Stokes and lattice Boltzmann method with non-Newtonian fluids have been done by the different authors. Shupti et al [54] investigated the pulsatile non-Newtonian fluid flows in a model aneurysm with an oscillating wall. A lattice Boltzmann simulation of non-Newtonian power-law fluid flows in a bifurcated channel with low Reynolds number has been studied by Siddikk et al [55].…”

Pressure-Driven Thermal Slip Flow in the Elliptical Channel with Radial Oscillatory Wall

“…In literature, the governing equations of the oscillatory flow of fluid in the duct with oscillating wall are the continuity equation and the Navier-Stokes equations subject to either no-slip or slip boundary condition. Various studies considered two-dimensional oscillating flow in the duct with fully oscillating wall [3][4][5][6][7][8][9], partially oscillating wall [10,11], and stretching sheet [12]. Three different directions of wall oscillation including the transverse (axial), vertical (radial), and both directions have been applied to the model.…”

“…Espin and Papageorgiou [7] investigated the stability of viscous pressure-driven flows in the channel with vertically oscillating walls and determined the numerical solutions for the Reynolds number ranges as an increase of wall oscillations amplitude. Shupti et al [8] studied the two-dimensional pulsatile flow of blood through a stenosed artery which was assumed to be moving sinusoidally in the cross-section direction. The computational domain where a cosine-shaped aneurysm occurring after an appearance of a cosine-shaped stenosis causes the variation of the height of the domain.…”

Coupled Numerical Scheme for Vascular Fluid-Tube Interaction using Large Deformation Theory

“…Later on, Finol et al used a three-dimensional model of AAAs with a single, asymmetric and rigid aneurysm using the finite element method [31]. More recently, more realistic numerical studies on blood dynamics based on rigid wall models are elaborated in [32][33][34][35][36][37][38]. By considering the blood flow to be pulsatile, the FSI models are favorable for understanding both the behavior of the blood and the dynamics of the arterial aneurysm [39].…”