Numerical simulation of non-Newtonian blood flow dynamics in human thoracic aorta

Abstract

Three non-Newtonian blood viscosity models plus the Newtonian one are analysed for a patient-specific thoracic aorta anatomical model under steady-state flow conditions via wall shear stress (WSS) distribution, non-Newtonian importance factors, blood viscosity and shear rate. All blood viscosity models yield a consistent WSS distribution pattern. The WSS magnitude, however, is influenced by the model used. WSS is found to be the lowest in the vicinity of the three arch branches and along the distal walls of the branches themselves. In this region, the local non-Newtonian importance factor and the blood viscosity are elevated, and the shear rate is low. The present study revealed that the Newtonian assumption is a good approximation at mid-and-high flow velocities, as the greater the blood flow, the higher the shear rate near the arterial wall. Furthermore, the capabilities of the applied non-Newtonian models appeared at low-flow velocities. It is concluded that, while the non-Newtonian power-law model approximates the blood viscosity and WSS calculations in a more satisfactory way than the other non-Newtonian models at low shear rates, a cautious approach is given in the use of this blood viscosity model. Finally, some preliminary transient results are presented.

Numerical Investigation of the Effects of Prosthetic Aortic Valve Design on Aortic Hemodynamic Characteristics

“…Despite the fact that the blood flow in the vascular system was pulsatile under physiological conditions, several numerical [73,74] and in vitro [75][76][77] studies have suggested that steady-state simulation can predict the non-temporal related flow characteristics at the corresponding point of the pulsatile flow profile. In addition, it has been reported that the WSS distribution patterns derived from the steady flow simulations are similar to the time-averaged WSS (TAWSS) from the unsteady analyses [67,78,79].…”

Computational Fluid Dynamics Modelling and Simulation of an Inclined Horizontal Axis Hydrokinetic Turbine

“…The results presented in Figure 15 show that the employed CFD simulations are appropriate enough to be used in the computations of HAHTs. References [35][36][37] measurements, at least in the three computed TSR, a fact that is attributed to the better performance of the SST model regarding the k-ε model in these kinds of rotating machines [27]. The results presented in Figure 15 show that the employed CFD simulations are appropriate enough to be used in the computations of HAHTs.…”

Meshing strategy for bifurcation arteries in the context of blood flow simulation accuracy

“…A literature study conducted for this research [3][4][5] shows that computational grids created for the analysis of blood flow in an artery are, typically, unstructured triangular and tetrahedral meshes prepared for inviscid computations The results of the numerical analysis of blood flow ⇤ e-mail: natalia.gr.lewandowska@doctorate.put.poznan.pl conducted on such meshes are flawed. Low quality and no inflation layer grids do not provide the necessary resolution to model the detachment of the boundary layer in the flow.…”