Abstract
Created by the gravitational pull of the moon and sun, the ocean current can be predicted with complete accuracy. Tidal turbines convert the power in ocean currents to energy, by reducing the flow velocity, making this a predictable and reliable resource. A key component of the tidal turbine is the blades, where their quality in manufacturing has a non-negligible influence in energy conversion. To assess the structural performance of a tidal turbine blade, experimental testing, including material testing, natural frequency testing, static testing, and accelerated fatigue testing, can be carried out. However, the blade surface quality is also important for the tidal turbine blade, as it influences its hydrodynamics. An inferior quality surface may have a negative influence on the turbine performance, by resulting in a larger operation load and/or less energy production efficiency. This research uses 3D laser scanning, an advanced survey technique, to assess the surface quality of a 1-MW tidal turbine blade. The blade is 8-m long and made from a novel glass-fibre reinforced polymer (GFRP) composite material. A methodology for blade manufacturers to assess the surface accuracy without compromise to the blade due to the non-intrusive nature of the scanning process are described. The geometries of the manufactured blade and the moulds are captured by a Leica Scan Station C10 3D laser scanner. By comparing the scan results, the manufactured blade surfaces are proved to be in good agreement with the moulds.