Abstract
For the improvement of rotor performance for the horizontal wind turbines, the winglets attached at blade tips have been attempted. It can move the shedding position of the tip vortices away from the blade tips to the tip of the winglets, which decreases the axial induced velocity in the rotor plane, leading to the increase of the rotor output. The similar effects can be expected in the sweepback rotor blades andlor rotors with coning angle for the output augmentation. The present paper describes the influence of sweep and coning angles of the rotor blades to the flow field around the rotor blade, and the blade load, which are analyzed by a panel method with free wake model. The results show the possibility of the performance improvement by adopting the rotor blade with sweep or coning angle.
