Vascular wall flow-induced forces in a progressively enlarged aneurysm model.

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Computational Science

Background:

• Abdominal aortic aneurysms (AAAs) pose significant health risks.
• Understanding blood flow dynamics within AAAs is critical for predicting rupture risk.
• Existing models often simplify blood rheology, potentially affecting accuracy.

Purpose of the Study:

• To numerically investigate unsteady blood flow in an abdominal aortic aneurysm model.
• To analyze the distribution of flow-induced forces on the aneurysm wall.
• To examine the impact of aneurysm growth and non-Newtonian blood properties on these forces.

Main Methods:

• Utilized a computational fluid dynamics (CFD) code based on the finite volume method.
• Employed the Quemada non-Newtonian model to simulate blood's two-phase rheological behavior.
• Compared results with a Newtonian flow model and analyzed three degrees of aneurysm growth.

Main Results:

• Characterized the flow field and distribution of flow-induced forces within the AAA model.
• Demonstrated variations in pressure and wall shear stress distributions with increasing aneurysm size.
• Highlighted differences between Newtonian and non-Newtonian blood flow simulations.

Conclusions:

• Aneurysm growth significantly alters flow patterns and wall stress distributions.
• Non-Newtonian blood properties influence the hemodynamics within AAAs.
• Findings provide insights into the biomechanics of AAA progression and potential rupture.