General Description

The process of designing wind turbine blades is closely connected with the development of airfoils. Traditionally wind turbine blades have been based on aviation airfoils designed for plane wings flying at completely different flow regimes than the turbine blades. Later on some research institutes and universities developed wind turbine specific airfoil shapes, tailored to the performance requirements of wind turbines.

The developments however of wind turbine designs have been rapid and current wind turbines are larger than ever before with rotor diameters in excess of 120m. These rotors are required to perform quietly and efficiently with low aerodynamic loads at turbulent and rough atmospheric conditions. Furthermore the aerodynamic performance of wind turbines should be constant through time despite the gradual contamination of the blades which constantly operate in rough conditions. 

The researchers of SMART BLADE have performed extensive research on the topic of blade performance degradation due to manufacturing and environmental conditions. The results of this research were published on a scientific publication presented at the ASME Turbo Expo Conference in Glasgow, Scotland in June 2010.

>> Dowload the Abstract of this paper in .pdf

Custom Airfoil Design

Lately some wind turbine manufactures have started developing in-house airfoil designs which are specifically tailored to the requirements of each wind turbine design. These airfoils are able to perform optimally since they are specifically designed with the aerodynamic and environmental conditions of the turbine model in mind.

SMART BLADE has developed and continues to expand in-house codes for the design and simulation of airfoils. Reverse airfoil design codes allow the generation of airfoil contours based on operational and aerodynamic requirements. The final airfoil shape is therefore not a mathematical function, but a resulting shape that satisfies the boundary conditions set by the designer. 

The airfoils developed by SMART BLADE are extensively simulated in detail with high order CFD codes in order to identify their performance. Minor changes of the profiles might be performed after the examination of the CFD simulation results. The final validation of the performance of each new airfoil happens of course at the wind tunnel. A test wing is designed and machined and is then tested at the wind tunnel of H.F.I TU Berlin.

3D structured grid for the numerical investigation of a custom airfoil [Source: SMART BLADE]
CFD simulation of a custom airfoil at high angle of attack at high...
...and at low speed flow conditions [Source: SMART BLADE]