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Tuesday, 11 March 2014
11:15 - 12:45 Advanced rotor technologies
Hardware Technology  


Room: Tramuntana
Session description

The Rotor is the key item for development of wind turbines. This includes e.g. power curve / production, turbine loads, safety and noise. In this session three developers / manufactures will contribute their know-how on research, development and validation of the new developments, i.e. CFD and measurements. The session will be completed by an outlook for the future trends within the Rotor technologies.

Learning objectives

  • State-of-the-art rotor technologies
  • Outlook for future rotor technologies
Lead Session Chair:
Ole Kjær, DNV GL Renewables Certification, Denmark
Pieter Segers Gamesa, Spain
Co-authors:
Segers Pieter (1) F P
(1) Gamesa, Madrid, Spain

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Presenter's biography

Biographies are supplied directly by presenters at EWEA 2014 and are published here unedited

Pieter Segers holds a degree in aerospace engineering from the University of Delft, where he specialized in aerodynamics and aero-elastics of rotors. He has previously worked in the aircraft and helicopter industry, and is currently employed in Gamesa as the team leader of the aerodynamics team of the 2.0-2.5MW platform, where he led the aerodynamic design of the G114 blade.

Abstract

Aerodynamic design of the GAMESA G114 blade

Introduction

As part of the endeavour for continuous innovation GAMESA has recently finalized the design of the new G114-2.0MW wind turbine, representing the lowest capacity factor of the market. This turbine was intended as the new addition to the 2.0MW platform, enabling commercial power extraction from the wind for ever lower wind speeds. The G114 blade was optimized for annual energy production whilst complying with noise, loads, and structural requirements. This paper / presentation will focus on the design of the G114 blade; several aerodynamic and aero-acoustic aspects of the design process will be addressed.

Approach

Blade design was accomplished as an optimization effort between aerodynamic, loads, structural and acoustic aspects. The design was kick-started with a trade-off of various blade concepts, and progressed with a few concepts that were taken forward to be fine-tuned over the various stages of project development. After several iterative loops of aerodynamic, loads and structural calculations a mature aerodynamic and structural blade design was reached.

Main body of abstract

Two new airfoils were developed in order to make the G114 blade a success. These airfoils were designed in-house as a direct extension of the existing GAMESA low noise high performance airfoils, and they were tailor-made for use on the G114 blade in order to match maximum structural efficiency with high annual energy production and low loads. The profiles include a high thickness high performance profile with curtailed lift curve meant as a mid-span airfoil, and a very high thickness high lift profile for use at the blade root. Details about the design process will be presented, including performance, structural, geometric and loads considerations. The design was accomplished using CFD and was validated in a low turbulence wind tunnel for both clean and dirty conditions. Details about the wind tunnel testing campaign and validation of the airfoil polars with wind tunnel data will be treated.

Blade geometric definition and performance were obtained using in-house Blade Element Momentum theory code and a blade optimizer code. After lofting, a 2.5D stationary RANS calculation was performed in order to validate the aerodynamic design, check the various aerodynamic parameters and validate the powercurve. Turbine noise was estimated using an in-house class II wind turbine noise emissions tool.


Conclusion

Finally, a complete "wind turbine virtual model" has been built as an unsteady RANS model including rotor, spinner, nacelle and tower. This model is firstly intended as an extra step of validation of the turbine performance, and secondly as prime support for the real prototype: the machine's transfer function and detailed influence of turbine components can be determined. Details about the set-up of the model and the validation methodology will be discussed.

Currently, the G114 2.0MW has obtained the Design Assessment by DNV and first prototype is being erected in the mountain range of Alaiz, close to Pamplona, Spain.



Learning objectives
Delegates will gain insight in the Gamesa blade design methodology and the aerodynamic and aero-acoustic aspects of the G114 blade in particular. This paper / presentation will highlight the complex nature of wind turbine blade design and how within Gamesa - as a commercial turbine manufacturer - different disciplines and conflicting requirements are integrated to achieve the final blade shape.