[MS04] Cardiovascular Flow: Modelling, Simulation & Experiment

[MS04-02] Pulsatile flow dynamics in an artery with multiple pathologies: A Fluid- Structure Interaction study

*Priyanshu Soni¹, Abhra bhattacharya¹, Abdullah Y Usmani², Sanjay Kumar Rai¹, B V Rathish Kumar³ (1. School of Biomedical Engineering, IIT BHU Varanasi India (India), 2. Department of Mechanical Engineering, Zakir Husain College of Engineering and Technology AMU, Aligarh India (India), 3. Department of Mathematics & Statistics, IIT Kanpur, India (India))

Keywords:

Fluid-Structure Interaction,Computational Fluid Dynamics,Viscoelastic Artery,Stenosis,Aneurysm

Cardiovascular diseases are a major cause of premature mortality, often due to arterial stenosis and aneurysms. This study investigates the interplay between hemodynamics and biomechanics in arteries with coexisting stenosis and aneurysms using one-way fluid-structure interaction (FSI) modeling. Three-dimensional artery models with stenosis severities of 50%, 70%, and 90% (Cases 1–3) and an eccentric model (Case 4) are created, each featuring a 50% downstream aneurysm to examine its interaction with upstream stenosis. The viscoelastic arterial wall, modeled with a 2.5 mm thickness using a generalized Maxwell model, is subjected to physiological pulsatile velocity and pressure profiles to simulate realistic blood flow conditions. FSI analysis captures key hemodynamic indicators along with biomechanical responses, including arterial wall deformation and von Mises stress. Results reveal severe stenosis ( >70%) induces intense, persistent vortical structures and promotes pronounced three- dimensional flow disturbances, significantly increasing thrombus risk, aneurysm progression, and localized wall stress, especially in 90% stenosis (Case 3). Vortical dynamics become more complex with stenosis severity, with eccentric stenosis introducing asymmetry, leading to wall- adjacent vortex migration and prolonged flow disturbances. Eccentric stenosis (Case 4) redistributes shear stress, reducing localized stress concentrations but maintaining complex flow patterns, causing the highest wall deformation of 1.9 mm and peak von Mises stress of 8.8 kPa, respectively. Severe stenosis requires urgent medical attention due to increased rupture risk, while eccentricity moderates localized stress yet sustains vascular risks. This study highlights role of FSI in connecting flow dynamics with arterial biomechanics, aiding in vascular risk assessment and targeted surgical interventions.