Fluid structure interaction of turbulent flows with complex-shape bodies

From industrial processes to biological systems, understanding fluid-structure interactions (FSI) in turbulent flows with complex-shaped bodies is essential for optimizing natural and engineered systems. This dissertation investigates FSI across different regimes, using numerical simulations, experimental methods, and data assimilation to explore phenomena such as turbulent multiphase flows and cardiovascular dynamics.

Chapter 1 studies heavy chiral particles in homogeneous isotropic turbulence, showing how their chirality couples translational and rotational motions, generates mean flow vorticity, and either suppresses or amplifies turbulence depending on parameters like turbulence intensity, density ratio, and volume fraction. Energy spectra reveal notable turbulence suppression at high volume fractions. Chapter 2 extends this investigation to light chiral particles, which, due to lower inertia and added mass effects, exhibit persistent coupling dynamics that reshape flow interactions and turbulence modulation.

Chapter 3 examines the settling of oloid-shaped particles in quiescent fluid, revealing complex tumbling and oscillatory motions influenced by initial orientation. Simulations and experiments align well, although experimental limitations underscore the need for enhanced setups for more accurate representation. Chapter 4 develops a computational cardiovascular model derived from patient-specific imaging data. Utilizing a nudging-based data assimilation approach, this model captures key functional parameters without requiring electrophysiological models, addressing challenges in anatomical segmentation and paving the way for improved fidelity in simulating cardiac dynamics.

This work highlights the interplay between numerical, experimental, and data-driven methods in addressing complex FSI problems. Future research could expand the study of chiral particles to shear-driven systems and small-scale turbulence energetics, while anisotropic particle settling requires broader exploration across Reynolds numbers and geometries. In cardiovascular modeling, integrating advanced imaging techniques and detailed valve dynamics could significantly enhance predictions and understanding.

In conclusion, this dissertation provides novel insights into fluid-structure interaction systems, advancing knowledge in both engineering and biomedical applications.