Print Email Facebook Twitter Trailing-edge serrations effect on the performance of a wind turbine Title Trailing-edge serrations effect on the performance of a wind turbine Author Llorente, Elena (Nordex Energy Spain S.A.U.) Ragni, D. (TU Delft Wind Energy) Date 2020-03-01 Abstract An experimental study focusing on the change of the aerodynamic performance of a wind turbine with the employment of trailing-edge serrations is presented. The design procedure which starts from the serration design, together with the experimental wind tunnel testing and the installation in an already operating wind turbine is discussed. A prediction methodology to estimate the aerodynamic performance change of the machine with the blade add-on is validated by in-field measurements. Wind tunnel experiments for the validation of the original serration design have been carried out on a Nordex ADO30 airfoil with a relative thickness of 30% and on a NACA643418 airfoil with 18% thickness. The two airfoils are respectively used in this study due to their peculiar characteristics. While the first has been designed for relatively high Cl/Cd performance versus structural integrity (i.e. relatively high thickness), the second one is a typical reference airfoil used in wind turbines for its interesting Cl/Cd performance in both laminar and rough conditions. Clean and rough conditions have been tested in order to prepare a database for the analysis of the full turbine in several wind conditions. Aerodynamic forces with the serrated trailing-edge extensions are measured for different angles of attack and serration flap angles. The results are further discussed and employed for the analysis of the full rotor. Results already show that an increase in the flap angle is typically associated with an increment in lift, but not necessarily in drag. This has a beneficial effect on the operational regime of the machine when taken into account. The influence of the trailing-edge serrations on an operating wind turbine has been quantified in terms of total loads and energy production. The power curves with and without the trailing-edge installations are further analyzed and compared with the theoretical predictions. • Experimental tests show big impact of serrations on airfoil's aerodynamic properties • Predictive law used for extending the serrations influence to the whole blade • Theoretically, serrations have positive impact on power production of wind turbines • Theoretically, serrations increase wind turbine loads and reduce its life-time • Positive impact of serrations on power production of real machines has been probed Subject Aerodynamic coefficientsFlap angleTrailing-edge serrationsWind tunnel testsWind turbine loadsWind turbine power curve To reference this document use: http://resolver.tudelft.nl/uuid:91f37134-e650-463c-86fe-67dc841a1c55 DOI https://doi.org/10.1016/j.renene.2019.08.128 Embargo date 2020-07-01 ISSN 0960-1481 Source Renewable Energy, 147, 437-446 Bibliographical note Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. Part of collection Institutional Repository Document type journal article Rights © 2020 Elena Llorente, D. Ragni Files PDF 1_s2.0_S0960148119313151_main.pdf 2.25 MB Close viewer /islandora/object/uuid:91f37134-e650-463c-86fe-67dc841a1c55/datastream/OBJ/view