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This thesis advances the understanding of turbulent erosion wear in particle-laden flows by investigating the role of coherent turbulent structures—particularly Large-Scale Motions (LSMs) and, potentially, Very Large-Scale Motions (VLSMs). These structures account for a significant contribution of the turbulent kinetic energy, being up to 60%, which can be transferred to entrained particles, driving them toward surfaces and causing erosion. The analysis reveals clear evidence about correspondence between the dynamics of these structures and the experimentally observed impact velocities and angles derived from wear scars, thereby confirming the central hypothesis that turbulent structures govern the erosion process.
Key flow and particle parameters including: Reynolds number, Stokes number, particle concentration, impact angle, and velocity. These parameters were found to influence the frequency and distribution of erosive impacts. The study integrates advanced simulation techniques (Large Eddy Simulation coupled with Multi-Phase Particle-in-Cell modelling) and innovative experimental tools such as Ultrasound Particle Imaging Velocimetry (UPIV) and Particle Tracking Velocimetry (PTV) to characterize both the fluid-phase turbulence and the resulting particle behaviour near solid boundaries.
Importantly, the findings support a shift toward energy-based erosion models that consider eroded surface hardness and resolved flow structures, moving beyond traditional yield stress-based formulations. A reduced-order analysis using POD and wavelet transforms revealed that a small number of energetic modes could predict the spatio-temporal coherence of sweep events responsible for particle impacts. Additionally, the use of surrogate particles matched by Stokes time response enabled efficient simulations of large experimental particles without compromising LES resolution.
Although challenges remain in quantifying long-term surface mass loss and resolving near-wall effects in greater detail, this work establishes a robust framework for predictive modelling of erosion wear. It proposes the fundaments for future development of more accurate, computationally efficient, and experimentally validated models applicable to industrial systems such as pipelines and slurry transport infrastructure.