Advanced laser-based surface engineering for applications in the energy sector

Escudero Ornelas, Aland 2025. Advanced laser-based surface engineering for applications in the energy sector. PhD Thesis, Cardiff University. Item availability restricted.

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Abstract

Improving the performance of energy system components, such as turbines and heat exchangers, is vital for reducing energy waste and emissions. However, the design of functionalised surfaces remains largely reliant on trial-and-error methods, which are time-consuming, resource-intensive, and often overlook the coupled effects of surface geometry, manufacturing variability, and long-term behaviour. In particular, the ageing of laser-textured surfaces and their evolving surface chemistry are poorly understood, limiting the industrial scalability of microtextures. This thesis presents a predictive optimisation framework that integrates laser surface texturing (LST), computational fluid dynamics (CFD), optimisation algorithms, and surface chemistry analysis to design and evaluate microtextures for energy applications. By combining high-fidelity simulations with algorithmic optimisation, the framework streamlines texture selection and parameter tuning, addressing key limitations of conventional workflows. Experiments showed that optimised biomimetic textures, such as triangular patterns, reduced boundary layer thickness by up to 21.3% under turbulent airflow. CFD predictions based on real-texture geometries achieved accuracies within 6.44%, while idealised CAD-based simulations deviated by over 18%, highlighting the importance of using actual fabricated surfaces in predictive models. The thesis also explores the long-term wettability evolution of laser-textured surfaces. Contact angle measurements revealed a transition in channel textures from hydrophilic (64.24° on Day 0) to strongly hydrophobic (135.55° after 45 days), while cross-hatch textures increased moderately from 88.21° to 115.22°. X-ray photoelectron spectroscopy (XPS) and energy-dispersive spectroscopy (EDS) linked these changes to progressive oxidation, elemental redistribution, and the formation of mixed oxide layers. These chemical transformations significantly influenced surface energy states, showing that wettability ageing is governed more by surface chemistry than geometry alone. This research presents a scalable, experimentally validated methodology for laser-based surface engineering that integrates manufacturing precision, fluid dynamics, and chemical ageing. It provides a robust framework for designing durable microtextures that deliver energy savings, lower emissions, and longer component lifespans.

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Schools > Engineering
Uncontrolled Keywords:	1. Microtexture 2. Laser Texturing 3. Biomimetic Textures 4. Optimisation 5. Computer Fluid Dynamics 6. Surface Chemistry
Date of First Compliant Deposit:	6 January 2026
Last Modified:	06 Jan 2026 14:30
URI:	https://orca.cardiff.ac.uk/id/eprint/183574

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