[MS04] Cardiovascular Flow: Modelling, Simulation & Experiment

[MS04-01] Flow Hemodynamics in Cardiovascular Pathologies: A Biomechanical Perspective

*Abdullah Yousuf Usmani¹ (1. Assistant Professor, Department of Mechanical Engineering, Zakir Hussain College of Engineering and Technology, AMU Aligarh (India))

Keywords:

Hemodynamics,Particle Image velocimetry,Arterial diseases,Respiratory flow

The research investigates pulsatile flow hemodynamics in deformed vasculatures, focusing on the role of wall compliance and altered flow dynamics in vascular pathologies, including aneurysms, stenoses, and intracranial aneurysms. Using Particle Tracking Velocimetry (PTV) and Particle Image Velocimetry (PIV), the study examines the temporal and spatial characteristics of flow, wall deformation, and fluid-structure interactions. Results reveal that wall compliance significantly influences flow dynamics, amplifying chaotic behavior, vortex formation, and flow disturbances while reducing wall shear stress (WSS). These effects, quantified through parameters such as Largest Lyapunov Exponents (LLE), highlight the biomechanical vulnerability of arterial walls to disease progression and rupture under pathological conditions.The study spans several vascular scenarios exhibiting aneurysms and stenosis. In compliant abdominal aortic aneurysms (AAA), increased flow velocities, broadened velocity spectra, and periodic wall displacements are observed, with regions near the bulge neck showing the highest strain and rupture susceptibility. Stenosed geometries exhibit high-velocity jets and downstream recirculation zones, with compliant models amplifying flow disturbances during retrograde phases. For intracranial aneurysms, varying inflow orientations reveal distinct vortex patterns, with high wall pressures and WSS gradients in regions of flow impingement, emphasizing the impact of arterial geometry on hemodynamic factors.Complementary PIV experiments around aortic valves provide insights into valvular hemodynamics under pulsatile flow conditions, capturing detailed vortex formation in the sinus region. Respiratory flow studies focus on Expiratory Dynamic Airway Collapse (EDAC) in COPD patients, where pressure drops in upper and lower respiratory tracts are measured to understand airflow resistance during expiratory phases. These findings contribute to the understanding of respiratory pathophysiology, offering valuable insights into the mechanical basis of airway obstruction.By integrating experimental techniques and physiological modeling, this work bridges gaps between biomechanics and clinical research, providing a framework for analyzing the interplay between flow dynamics, structural compliance, and disease progression. The outcomes have implications for improving diagnostic precision and therapeutic interventions for vascular and respiratory conditions.