Accurate knowledge of the aerodynamic forces, particularly drag and the limits of the lift coefficient for stable operation are essential for the design of an efficient kite energy system. The system in the present project also involves autonomous manoeuvring of the kite and therefore knowledge of control derivatives is very important. Lift, pitch and roll moments induced by small changes in camber at the trailing edge, and downward curvature at the tips (anhedral) will therefore be studied. Because of the importance of drag, effort will also be directed to the minimisation of the parasitic drag of the bridle lines. The Imperial College contribution to the project will measure the above listed aerodynamic forces under controlled wind tunnel conditions at reduced scale. The results will be compared with field testing experience obtained in another section of the project and then used as inputs to the analysis tool which predicts the operational characteristics of the kite energy system. The second contribution from Imperial College will be to extend and validate the modelling of the kite aerodynamics under orbiting and manoeuvring conditions, in particular developing the wake modelling to achieve greater accuracy and understanding of the issues raised by running two kites with operational overlap in the system, and to consider effects of mean wind shear and turbulence.

Potential Impact:
The UK offshore wind sector is projected to grow to £8bn by 2020 so the economic benefits estimated to result from the new kite energy modelling tool could be considerable across the UK investment. Research results will be communicated through the project partners and publication in relevant journals.