Wind power
Intelligent control of rotor blade aerodynamics

The rotor blades of wind turbines are exposed to continuously varying wind strengths and turbulence. These constantly changing stresses must be individually compensated for each rotor blade. Until now, this has been done by adjusting the pitch angle to the current situation. However, this method is not suitable for large rotor blade diameters. The project partners in the TOpWind research partnership are therefore developing intelligent elements that are locally integrated into the rotor blades. These can react quickly to flow changes. The aim is to improve the energy yields of the wind turbine and reduce sound emissions.

Reacting to aerodynamic loads

The size of wind turbines is constantly increasing and rotor blade diameters of over 120 metres on land and over 160 metres at sea present major aerodynamic and aeroacoustic challenges. The direction and speed of the wind can change suddenly and at any time. This process, known as wind shear, occurs when two immediately adjacent layers of air, which have different properties, flow past each other. This causes large forces to act on the rotor blades. Previous approaches focused on controlling these stresses individually via the pitch angle, which involves adjusting the pitch of each rotor blade (Individual Pitch Control (IPC)). This solution did not prove successful for the new large rotor diameters, despite the lighter construction of the rotor blades. Active flow control offers an interesting alternative to individual pitch control. Intelligent elements integrated locally into the rotor blades react directly to flow changes. In the future, they may allow the use of lighter and even longer blades. This is where the project TOpWind, short for "Technological and economic consideration of the application of active flow control to optimise the wind yield of wind turbines", comes in.