Testing of a new morphing trailing edge flap system on a novel outdoor rotating test rig

The morphing trailing edge system or flap system, CRTEF, has been developed over the last 10 years at DTU Wind Energy. After a promising wind tunnel test of the system in 2009 the INDUFLAP project has been carried out from 2011-2014 to transfer the technology from laboratory to industrial manufacturing and application. To narrow the gap between wind tunnel testing and full scale prototype testing we developed the rotating test rig. The overall objectives with the rotating test rig are: 1) to test the flap system in a realistic rotating environment with a realistic g-loading; 2) to measure the flap performance in real turbulent inflow and 3) to test the flap system in a realistic size and Reynolds number when comparing with full scale applications.. The rotating test rig consists of a 2.2m blade section attached to a 10m boom and mounted on a 100kW turbine platform. It was installed in June 2014 and a short measurement campaign was conducted in the autumn 2014. An important result of testing the flap system on the rotating test rig was operation of the flap system up to 30 rpm. which a g-loading of 9-10g comparable with the conditions on a 2-3MW turbine. Another important result was the measured performance of the flap system. We found that about 5.0deg. flap angle gives the same load change as 1deg. pitch. This is somewhat lower than simulations have shown which are in the range of 2 to 3 deg. flap angle to 1deg. pitch angle for a 15% flap. The realistic, turbulent inflow is probably a major cause of this lower performance.