At this year’s EWEA annual conference, Deutsche WindGuard & BIMAQ (Bremen Institute for Metrology, Automation and Quality Science) were awarded a prize for their poster on thermographic rotor blade measurement.
Deutsche WindGuard already used the procedure in a number of onsite measurements for customers. The measurement process was refined in cooperation with BIMAQ. By using a high-speed, high-definition thermography camera, it is possible to measure and thereby visualize even the slightest difference in temperature on the surface of a rotor blade on an operating wind turbine.
Different flow regimes (laminar or turbulent) affect the performance of an airfoil, but also the heat transfer between the rotor blade surface and the air, making the blade area with laminar flow warmer. A premature laminar/turbulent transition can be an indication of damages, erosion or contamination, which can have a negative effect on the aerodynamic qualities of the blade. Furthermore, the effectiveness of aerodynamic add-ons on the blade can be assessed while the wind turbine is in operation.
The measurement procedure was displayed at the annual conference of the European Wind Energy Association in Barcelona last week and was received with great interest. The winning poster was one of the 6 chosen out of 300 participants, because of its high innovative capacity and market potential.
“The great advantage of using thermography is that it requires no preparation of the blades. All tests can be run from ground-level while the turbine is operating”, says Nicholas Balaresque, Managing Director of Deutsche WindGuard Engineering, “You do not need to call in an expensive working platform or use rope access. There is no need to stop the turbine, which would involve additional costs. With hub heights and rotor diameters getting higher and higher, measurement procedures like this become more and more important in the future.”
Press release, March 18, 2014; Image: WINDGUARD