Danish participation in IEA Wind Task 29 Mexnext-II - Model validation
Based on participation in the IEA Annex 29 Mexnext II, the objective is to validate and improve a number of different aerodynamic and aeroelastic numemrical models used by both research institutions and industry. In this way the project will contribute to a reduction of the safety factors on computation of loads, used in certification of wind turbines.
The objective is to contribute to an international buildup of a database of high quality experimental aerodynamic data to be used for studies of fundamental aerodynamic subjects and for validating numerical models.
As the name MexNext II indicates there is a close correlation to the former MexNext Annex 29. During this Annex the data from the so-called MEXICO experiment (Model Esperiments In Controlled Conditions) carried out in 2006 were analyzed. Besides detailed surface pressure measurements on the blades of the 5m diameter rotor, the MEXICO experiment also comprised unique flow measurements around the rotor and in the wake.
The work is organized in five work packages and the overall structure in the work is: WP1) Identify and evaluate the usefulness of the differnet data sets; WP2) Process the selected data to a suitable format and evaluate the uncertainties of the data; WP3) Set up a number of test cases and runcomputations on them with differnet aerodynamic and aeroelastic models; WP4) Carry out a deeper investigation of fundamental aerodynamic issues based on the comparison of model results and experimental data.
During the 3 year project, 20 leading institutes within the field of wind turbine aerodynamics cooperated closely in Mexnext II. Several ’historical’ measurements have been assessed as concerns usefulness and missing information and now added to the Mexnext data base.
Two major rounds for validation of models have been arranged during the project; one for uniform inflow to the rotor and one for yawed flow, respectively. DTU has participated in both rounds with a number of different models: HAWC2, EllipSys3D, Actuator Line (AL), BEM which has provided useful insight into the accuracy of the models and thus also can be used to determine which model is best suited for a specific load case. Further DTU has been leader of two tasks: 4.3 “Angle of attack investigations”, and of 4.8 “Dynamic Inflow” where a deeper investigation into these fundamental subjects have been carried out.
Key figures
Category
Dokumenter
Participants
| Partner | Subsidy | Auto financing |
|---|---|---|
| Danmarks Tekniske Universitet (DTU) | 0,78 mio. DKK | 0,33 mio. DKK |
Contact
Tlf. 4677 5047
