One of the costlier items in current tidal turbine designs is the rotor blades. This project aims to assess the performance implications of the adoption of innovative, labour-saving, mechanized manufacturing processes for large diameter horizontal axis tidal turbines (>15 m) which could effect a substantial reduction in their cost. Current design practice involves consideration of the performance of tidal turbines in essentially quasi-steady operating conditions. The experience in the field, however, points to the fact that in energetic tidal locations the levels of in-stream turbulence are such as to impact negatively on their performance. The feasibility of combining lower cost manufacturing techniques for blades operating in turbulent tidal environments, with simpler designs which are tolerant of the transient operational conditions will be examined. The project seeks to establish what attendant modifications to an ideal datum design are involved in the streamlined construction and what are the performance implications of such modifications. The work will involve theoretical and experimental phases and will be carried out by a practised team of blade manufacturers and testing, design and analysis specialists

The team in Cranfield composed of Dr Joao Amaral-Teixeira and Dr Florent Trarieux will undertake the assessment of the performance of a selection of proposed rotors. This project will be undertaken in close collaboration with Nick Barlow, Founder and Managing Director of Southampton based leading composite blade manufacturer, Designcraft Ltd. The project is articulated around four phases of review of current manufacturing techniques, novel blade profile selection, numerical assessment using Blade Element Momentum models and state-of-the-art tank tests in three different tanks of increasing size, flow actuation type and turbulence levels: Cranfield Towing Tank, Haslar Towing Tank and Boulogne-sur-mer Circulation Channel.

Potential Impact:
This research will be very much relevant to UK Tidal Energy Industry and particularly for tidal developers considering large arrays with rotors > 15 m diameter.