Titel: Visualization of the elastic blade motion of an operating wind turbine, FOI-R-1398-SE
Författare/Author: Göran Ronsten
Utgivare/Publisher: Totalförsvarets forskningsinstitut (FOI), Vindforsk
Årtal/Year: 2005
Ämnesord/Subject: Mekanik och aerodynamik
Sökord/Keywords: wind energy, blade motion, image analysis
Rapport (Pdf)
Sammanfattning/Abstract: Simulation of blade movements is nowadays a standard procedure used to design new wind turbine rotors as well as for verifying design load cases. The author’s ambition was to investigate the possibility to verify blade displacements and twist by means of digital photographic recording. The equipment chosen was state-of-the-art at the time when the project was started in 2001. Similar measurements were initiated in two EU-projects, [4] and [5]. Real-time evaluation of the tower movements have been presented in [3]. However, no official results concerning image analysis of blade motion have been presented by these projects.
Recent technical development in digital camera and computer technology has made the hardware solution chosen somewhat old fashioned. High resolution cameras now connect via “simple” serial data buses like IEEE1394 and USB 2.0. Edge detection software, a crucial part in digital image analysis, is still part of expensive software packages. This last digital fortress is about to change with modern operating systems like MacOSX 10.4 where such features are an integrated part of the operating system. Any future application of methods based on digital imagery has been greatly facilitated from the recent rapid development of these techniques.
Icing was investigated by analysis of measured data. Simultaneous load measurements and images were acquired. These data remain to be evaluated jointly. The load measurements have been analyzed in [1]. This report describes the steps taken to obtain the measurements of elastic blade displacement.