Modelling improvement wind turbine blades

Developments in offshore wind aim to reduce the cost of energy even further. Many of the innovations are driven by an increasing size of the wind turbine power and energy per unit. As a consequence the turbine blades become larger and more flexible. In the past only the in-plane and out-of-plane deformations of the blade were taken into account in aeroelastic analyses. However, as the length of the blades increase the torsional deformation becomes more and more important for an optimal power production, load reductions and the avoidance of aeroelastic instabilities like flutter.

Improved modelling and torsional flexibilty

The objective of the project is to enable more accurate designs of wind turbine blades by improved modelling and validation of torsional flexibility. The added value of more accurate blade torsion calculations increases significantly for larger and thus more flexible blades. The levelized cost of electricity (LCOE) is reduced by less use of blade material because of reduced loads and an increased yield of energy (AEP) due to an optimal aeroelastic blade design with respect to power production.

The activities in the VaStBlade project include:

• The development of improved structural blade (torsion) models
• Tests of two blades on the test rig of the WMC. An EWT blade and a GE blade. On the GE blade the systems of SSB Wind Systems and Technobis tft-fos are installed to measure the torsional deformation.
• On-site blade deformation tests on a GE prototype using the systems of SSB Wind Systems and Technobis tft-fos to measure the torsional deformation.
• Validation of the aeroelastic codes from TNO and WMC using measurements.
• Design of 10MW wind turbine blade applying the gained knowledge on torsional structural behaviour and the validated tools.

The result of the VaStBlades project are datasets with unique validation data, an improved structural blade model, validated aeroelastic tools and a 10MW wind turbine blade design.