Equinor ASA
Rotor blade shaped to enhance wake diffusion

Abstract:

A blade 20 for a horizontal-axis wind turbine rotor comprises a radially-outer, energy-extraction portion 32 and a radially-inner, ventilation portion 30. The radially-inner ventilation portion 30 is shaped to ventilate a central area 34 of a wake of the rotor during use such that it contains more kinetic energy compared to the wake from a conventional rotor design. The increased wind flow velocity at the centre 34 of the wake generates additional shear stresses, with corresponding turbulence development, which gives rise to increased wake diffusion.