Do Long Aorta Branches Impact on the Rheological Properties?

Abstract

Current studies dispute the effect of the aorta geometry and branches on how the hemodynamics parameters develop along the branches in 3D models. In constructing and modelling the aorta geometry, it is necessary to incorporate the different lengths of the bifurcation and branches. Previous studies modelled the aorta with simplified assumptions (idealized model) which gave rise to some differences between the model and clinical outcomes. However, these differences are minimal, and the results can still be validated against clinical trials. The Computational Fluid Dynamics (CFD) methods can also accurately simulate the stresses affecting the artery wall and the dynamic behavior of the blood flow in its pulsatile form. Therefore, the outputs from CFD analysis can be used to reduce the risk of disease complications and enable a better understanding of the effects of hemodynamic stresses. A comparison of the behavior of the Time-Average Wall Shear Stress (TAWSS), Oscillatory Shear Index (OSI), and Relative Residence Time (RRT) against two lengths of bifurcations and in the presence of Non-Newtonian Power Law blood flow properties is presented in this work. This study investigates the cardiac cycle transient analysis using the Laminar inviscid flow in FLUENT, ANSYS 2020R2. The results are promising and give ample support for further development of new diagnostic tools based on the relationship between the Wall Shear Stress (WSS) derivatives: TAWSS and the OSI and the branches lengths.