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The development design and testing of an industrial stall rotor with teeter and flexbeam


The objective of the project is the development of a two-bladed stall rotor with a teeter and flexbeam, which will result in a 20% reduction of the kWh costs, compared with a state of the art, stall turbine with a rigid rotor. The size of the rotor will be approximately 35m diameter.
The rotor will be designed for commercial series production. An integral part of the project is a feasibility study for upscaling to a megawatt size rotor. Development consists of several phases. The first phase is paid by NOVUM and is not included in the JOULE project. The second and third phases comprise the present JOULE project. These three phases involve the design of the stall-flexteeter rotor. The manufacturing and testing will be done in subsequent phases, which fall outside the scope of the present project.
The deliverable from the design phase is a final report describing the design of a stall rotor with a teeter and a flexbeam, based on an extensive feasibility and sensitivity study, and on extensive load calculations. The report includes an analysis of the improvement of the cost/benefit ratio, and the results of the upscaling study. The deliverable from the detail design phase is a package of drawings and reports which describe all the input required for the start of the manufacturing phase.

In order to give the European Windenergy industry more chances to grow, it is important to reduce the integral costprice of the turbines. There are possibilities in that respect if the forces acting on the turbine are reduced. These forces which mainly originate from the rotor, can be influenced positively by providing flexibility in the blades / rotor combination. The flexteeter development has been based on this fact.
In this case there is flexibility in the blades on the one hand and on the other hand these blades are fixed on the rotorhub hingingly. The flexibility in the blade is obtained by constructing the fixation part as a "platespring" a rectangular tube. The reduction of the forces in the top of the turbine nacelle has it's effect down to the foundation, so that the entire turbine can be designed lighter. To obtain this, it is important for the knowledge available to be concentrated. To realise this concentration in the widest sense, work has to be done on a European level, so that it will be easier to get access to Universities and Institutes.

Funding Scheme

CSC - Cost-sharing contracts


Aerpac Holding BV

7550 AN Hengelo

Participants (3)

Westerduinweg 3
Ecotecnia Sociedad Cooperativa Catalana Ltd.
23 1,Cl. Amistad
08005 Barcelona
229,Czaar Peterstraat 229
1000 AJ Amsterdam