Evaluating Uncertainties in CFD Simulations of Patient-Specific Aorta Models using Grid Convergence Index Method

TL;DR

This study evaluates how different mesh types and densities affect the accuracy and reliability of CFD simulations of patient-specific aorta models, using the Grid Convergence Index method to identify optimal meshing strategies.

Contribution

It introduces a systematic GCI-based approach to select the best mesh type for CFD aorta simulations, highlighting the advantages of polyhedral meshes.

Findings

Increasing mesh density reduces uncertainty in results.

Polyhedral meshes offer a good balance between accuracy and computational cost.

GCI values confirm the reliability of the simulation results.

Abstract

Cardiovascular diseases are among the most important causes of global mortality. Computational Fluid Dynamics (CFD) is a powerful research tool that analyzes the hemodynamics of artery and blood flow patterns. In this study, CFD simulations are performed to assess the patient-specific healthy aorta, fusiform, and saccular aneurysm with various mesh types, including tetrahedral, polyhedral, and poly-hexacore. The aim of this study is to explore how different mesh types and grid densities impact the hemodynamic properties of physiological flows, with the goal of identifying the most cost-effective meshing approach. A mesh independence study is carried out to ensure the precision of the results, considering the wall shear stress distribution. For this, five different mesh resolutions are generated for each geometry. The uncertainties of the simulations associated with the discretization techniques and solutions are evaluated using the Grid Convergence Index (GCI) method. The findings showed that increasing the mesh density provides smaller uncertainty. GCI values for the wall shear stress are in the range of convergence, indicating that the results are reliable and accurate. Mesh type selection affects the accuracy and computational cost of our simulations. The polyhedral and poly-hexacore meshes lead to a good compromise between precision and computational cost, while the tetrahedral mesh style gives the most precise results with fluctuation. This work provides a systematic approach based on the Grid Convergence Index method in order to select the most appropriate mesh type for evaluating uncertainties in CFD simulations of patient-specific healthy aortas and aortas with abdominal aneurysms. According to the findings and GCI analysis, the polyhedral mesh type was chosen for all patient-specific aorta models. The study clearly demonstrated its superiority over other mesh types, ...