Mapping blade angle effects for the erosion of polymer based composites: an approach to developing smart materials for tidal turbines

Tribology in marine renewable technologies has become of increasing interest due to the implications for developing improved materials for tidal and wave energy conversion devices. For tidal devices, the materials of interest are primarily polymer based composite materials that are used to provide structural integrity while reducing weight. These are specifically applied to turbine blades to withstanding the high impact loadings in sea water conditions. At present, current materials in test trials have demonstrated some limitaions in service. In this paper, fundamental research has been carried out to investigate tribological mechanisms of potential candidate composite materials to be used in tidal turbines by firstly considering the effects of various erosion parameters on the degaradation modes, with and without particles in sea water conditions. The erosion mechanisms of composite materials used in tidal turbine blades have been evaluated using Scanning Electron Microscopy techniques to analyse the surface morphologies following testing in water representative of the constituents of costal sea water. Generic erosion maps have been constructed as a first step approach to identify regions of minimum erosion for the operating conditions and to identify the significant effect of the sea water environment on the degradation of the composite.