Numerical Investigation of Blood Flow through an Aneurysm on Basilary Artery of Circle of Willis

Document Type : Mechanics article

Authors

1 University of Tabriz

2 university of Tabriz

3 Associated professor, University of Bonab

Abstract

Cerebral aneurysms are dangerous bulges in the walls of brain arteries that can lead to life-threatening hemorrhagic stroke if ruptured. Predicting their behavior and identifying high-risk regions through hemodynamic analysis is crucial in early diagnosis and therapeutic planning. In this study, blood flow within a saccular aneurysm located on the basilar artery of the Circle of Willis is numerically investigated using computational fluid dynamics (CFD). The geometry is modeled based on standard anatomical data from previous studies, and blood is considered as an incompressible, non-Newtonian, transient, and laminar fluid. Inlet boundary conditions are defined according to a realistic cardiac cycle, discretized into five key systole phases. The results present detailed distributions of velocity, pressure, and wall shear stress (WSS) fields within the aneurysm and parent artery throughout the cardiac cycle. Findings indicate that during systole, strong vortex formation occurs inside the aneurysm sac, leading to blood stasis. Approximately 16% of the incoming flow remains trapped within the aneurysm by the end of the third cycle. Moreover, wall shear stress significantly decreases in specific regions—particularly near the aneurysm dome—creating conditions conducive to thrombus formation and endothelial dysfunction, which may accelerate wall degeneration. Pressure fluctuations inside the aneurysm are also considerable, especially during peak systole, increasing the risk of rupture. These results highlight the critical influence of hemodynamic factors on aneurysm stability and rupture potential.

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Articles in Press, Accepted Manuscript
Available Online from 29 November 2025
  • Receive Date: 04 October 2024
  • Revise Date: 06 August 2025
  • Accept Date: 29 November 2025