A morphing trailing edge flap system for wind turbine blades

Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review


The development of a morphing trailing edge system for wind turbines, also called a flap system, is presented. The functionality is simple as the flap deflection is controlled by pressurized air or a fluid in a number of voids in the flap made of an elastic material. It is thus a robust system as no mechanical or metal parts are used. The prototypes tested in the laboratory and on a blade section in a wind tunnel in the period from 2007-2010 demonstrated the functionality and the aerodynamic performance of the flap concept. In a recent research and development project INDUFLAP from 2011-2014 the flap system has been further developed in corporation with the industrial partners Hydratech Industries (DK) and Rehau (DE). A new trailing edge flap design with spanwise voids (channels) and with a chord of 15cm suitable for a 1m chord blade section was developed. It was then manufactured by extrusion and glued together with a load carrying part with a connector part that allows an easy attachment on the blade section. After tests in the laboratory the flap was mounted on a 2m long blade section mounted on a newly developed test rig. A 10m long boom with the blade section was installed on a 100kW turbine hub where the original blades were taken down. It means that the flap system was tested under realistic rotating conditions with real atmospheric turbulent inflow and with a g loading up to 10g which represents the conditions on the outer part of a MW turbine blade. The measured performance of the flap system shows that 3 deg. flap deflection gives the same lift change as 1 deg. pitch of the whole blade section.
Original languageEnglish
Title of host publicationProceedings of the 7th ECCOMAS Thematic Conference on Smart Structures and Materials (SMART 2015)
EditorsA.L. Araújo, C.A. Mota Soares
Number of pages10
Publication date2015
Publication statusPublished - 2015
Event7th ECCOMAS Thematic Conference on Smart Structures and Materials - Ponta Delgada, Portugal
Duration: 3 Jun 20156 Jun 2015
Conference number: 7


Conference7th ECCOMAS Thematic Conference on Smart Structures and Materials
CityPonta Delgada
Internet address


  • Morphing trailing edge
  • Smart structure
  • Wind turbine blade
  • Load alleviation
  • Experimental validation


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