Tribological challenges of scaling up tidal turbine blades

Generating electricity from renewable resources (wind, wave and tidal) is of increasing interest. Of all marine renewables, tidal energy, by comparison, possesses the higher persistency and predictability over long time scales and the higher density of water than air results in greater power output from a tidal turbine than a wind turbine with similar dimensions. However, due to the nature of the tides, developing a reliable device for such environments, especially with an increased rotor diameter, raises more challenges to be addressed including the tribological challenges such as sediment erosion, cavitation erosion and their possible synergistic effects on the tidal turbine blades. This research focuses on testing and developing materials for improved tribological performance in tidal environments. This includes producing a variety of composite materials with different fibres and layouts reinforcement to evaluate two main tribological issues of composite materials in tidal environments: matrix cutting and reinforcement fracture using a loped test rig, which measures the effects of impact angle, particle size and concentrations at different tip speeds. The test samples are analysed using scanning electron microscopy (SEM) to conduct a surface topography and characterisation.