Erosion of tidal turbine blades in the marine environment is a major material challenge due to the high thrust and torsional loading at the rotating surfaces, which limits the ability to harness energy from tidal sources. Polymer–matrix composites can exhibit leading-blade edge erosion due to marine flows containing salt and solid particles of sand. Anti-erosion coatings can be used for more ductility at the blade surface, but the discontinuity between the coating and the stiffer composite can be a site of failure. Therefore, it is desirable to have a polymer matrix with a gradient of toughness, with a tougher, more ductile polymer matrix at the blade surface, transitioning gradually to the high stiffness matrix needed to provide high composite mechanical properties. In this study, multiple powder epoxy systems were investigated, and two were selected to manufacture unidirectional glass-fiber-reinforced polymer (UD-GFRP) plates with different epoxy ratios at the surface and interior plies, leading to a toughening gradient within the plate. The gradient plates were then mechanically compared to their standard counterparts. Solid particle erosion testing was carried out at various test conditions and parameters on UD-GFRP specimens in a slurry environment. The experiments performed were based on a model of the UK marine environment for a typical tidal energy farm with respect to the concentration of saltwater and the size of solid particle erodent. The morphologies of the surfaces were examined by SEM. Erosion maps were generated based on the result showing significant differences for materials of different stiffness in such conditions.

The tribological mechanisms of potential composite materials that could be used in tidal turbines considered the effects of various erosion parameters on the degradation modes, both with and without particles, in still and seawater conditions. The aim of this study was to investigate the potential of a specialised epoxy erosion-resistant coating for glass fibre-reinforced plastic (GFRP) in resisting the impact of slurry erosion. Slurry erosion is a process by which solid particles suspended in a fluid medium impinge on a surface, causing material loss due to repeated impacts. The coating efficacy was evaluated through a series of tests, including three different speeds and six different impinging angles and the results were used to generate tidal turbine maps. The study provided insights into the durability and of the epoxy and potential use of the coating in tidal turbine blade industries where resistance to erosion is crucial for long-term performance and safety.

Tidal energy, with its potential to provide a consistent energy output and reduce carbon emis-sions, has garnered significant interest. This study, which is the first to evaluate the performance of tidal turbines in seawater conditions involving sand particles, presents a novel approach. A slurry rig was developed to examine composite materials, and a glass fibre reinforcement poly-meric material was tested over a range of particle size, velocity, impact angle, and exposure time. The results, which show significant changes in the mass loss materials as a function of these variables, have profound implications for the design and performance of tidal turbines. The study also utilized a scanning electron microscope (SEM) and depth profiling analysis, and erosion maps were generated to demonstrate the changes in erosion mechanisms. These tools can be used to optimize such materials in tidal turbine conditions.

The ongoing depletion of global fossil fuel resources and the intensification of the greenhouse effect have made the development of renewable energy a universally prioritised objective. Tidal energy is one of the renewable energy sources that offers a viable alternative due to its excellent predictability, high energy density, and long-term stability. However, one of the primary challenges in tidal turbine applications is the erosion of turbine blades caused by challenging marine environmental conditions. This study investigates the erosion behaviour of glass fibre-reinforced polymer (GFRP) in aquatic conditions over an extended pre-exposure period of 183 days (4,380 hours). To achieve this, a custom-designed slurry erosion impingement rig was developed and is detailed in this paper. The results reveal serious changes in the erosive mechanisms of GFRP as a function of prolonged pre-exposure, with critical implications for the suitability of the material in tidal turbine blades for tidal energy applications. Advanced characterisation techniques, including erosion wastage maps, micro-profiling, and SEM, were employed to analyse surface degradation and erosion patterns. These tools provide insight into material performance and support the optimisation of GFRP for reliable, long-term operation in tidal energy environments.

This paper investigates the effects that rain drop erosion has on the integrity of wind turbine materials. This research involves analysis of impact models and theoretical equations to simulate the impact phenomena when a raindrop collides with a wind turbine blade at high speed. Impact phenomena that occur when a raindrop impacts with a wind turbine blade were evaluated. Additionally, the use of various types of software was considered to simulate this impact event. The model results of the raindrop impact with respect to a comparison of the governing equations and impact behaviour are addressed. Future work is outlined including adding variables to the erosion modelling algorithms.

The ongoing depletion of global fossil fuel resources and greenhouse effect of harmful emissions have made the development of renewable energy a universal priority. Tidal energy is one of the renewable energy sources that offers a viable alternative. However, one of the primary challenges in tidal turbine applications is the erosion of turbine blades caused by challenging marine environmental conditions. This study investigates the erosion behaviour of glass fibre-reinforced polymer (GFRP) in sea water conditions over an extended pre-exposure period of 183 days (4380 h). To achieve this, a custom-designed slurry erosion impingement rig was developed and is detailed in this paper. The results reveal significant changes in the erosion mechanisms of GFRP as a function of prolonged pre-exposure, with critical implications for the suitability of the material in tidal turbine blades for tidal energy applications. Advanced characterisation techniques, including erosion wastage maps, micro-profiling, and SEM, were employed to analyse surface degradation and erosion patterns. These tools provide insight into material performance and support the optimisation of GFRP for reliable, long-term operation in tidal energy environments. Graphical Abstract