The background for the project initiated in 2007 was a discussion and assessment in the project group of the uncertainties and shortcomings related to the reliable design of MW turbines. The most important issue is that the derivation of 3D airfoil data from 2D wind tunnel data still introduces uncertainty and conservatism in the rotor design process although different empirical correction methods have been developed.
Objectives
The overall objective of the project has been to provide an experimental basis that can improve our knowledge of a number of fundamental aerodynamic, aeroelastic and aeroacoustic issues and in general improve the design basis for MW rotors. Specifically the experiments were designed to provide new insight into:
- Correlation between 2D and 3D airfoil characteristics
- Boundary layer transition characteristics in 2D wind tunnel flow environment compared with full scale 3D rotor flow transition characteristics
- Inflow characteristics (shear and turbulence) on MW rotors with particular focus on the high frequency content
dynamic induction characteristics
- Wake flow characteristics
pressure fluctuations in the boundary layer influencing turbulent inflow noise and trailing edge noise
Approach
The selected experimental approach has been to carry out a number of coordinated, innovative measurements on full scale MW rotors as well as on airfoils for MW turbines in wind tunnels. Three type of measurements have been performed:
Collaboration
The project is a collaboration between Risø DTU and the industrial partners LM Wind Power, Siemens Wind Power, Vestas Wind Systems A/S and finally the utility company DONG Energy.
Funding
1/3 of the project is funded by the Danish Energy Research programme EFP-2007 under contract no.: 33033-0074
2/3 of the project are funded by Risø DTU and the collaborating companies
The project will continue in DAN-AERO II