Leading Edge Erosion of Wind Turbine Blades: Effects of Environmental Parameters on Impact Velocities and Erosion Damage Rate

2021 ◽  
Author(s):  
Amrit Shankar Verma ◽  
Zhiyu Jiang ◽  
Zhengru Ren ◽  
Julie j.e. Teuwen
Author(s):  
Amrit Verma ◽  
Zhiyu Jiang ◽  
Zhengru Ren ◽  
Weifei Hu ◽  
Julie Teuwen

Abstract The presence of rain-induced leading edge erosion of wind turbine blades necessitates the development of erosion models. The relative impact velocity between rain droplets and a rotating blade is an essential parameter for erosion modelling based on which the erosion damage rate of a wind turbine blade is calculated. The environmental parameters that govern such erosion damage have site-specific variations and differ for turbines installed at onshore and offshore locations. The present paper tries to provide guidelines for erosion modelling and investigates the differences in erosion of blade due to: (1) varying rainfall conditions modelled using different droplet size distributions for onshore and offshore locations, while interacting with (2) winds of varying turbulence intensities and (3) wave-induced loads. Aero-hydro-servo-elastic simulations are carried out for an onshore wind turbine and a monopile-supported offshore wind turbine. Further, erosion variables such as the relative impact velocities and the associated erosion damage rate of a blade are analysed for various blade azimuth angles. The study shows that the rainfall intensity and turbulence intensity influences the impact velocity and pressure minorly but has a substantial effect on the overall erosion damage rate. Also, a significantly higher erosion damage rate is found for blades exposed to offshore rainfall conditions than for blades under onshore rainfall conditions. Furthermore, no substantial influence on erosion is found because of wave-induced loads.


2021 ◽  
Vol 169 ◽  
pp. 953-969
Author(s):  
Leon Mishnaevsky ◽  
Charlotte Bay Hasager ◽  
Christian Bak ◽  
Anna-Maria Tilg ◽  
Jakob I. Bech ◽  
...  

2021 ◽  
pp. 0309524X2110071
Author(s):  
Usman Butt ◽  
Shafqat Hussain ◽  
Stephan Schacht ◽  
Uwe Ritschel

Experimental investigations of wind turbine blades having NACA airfoils 0021 and 4412 with and without tubercles on the leading edge have been performed in a wind tunnel. It was found that the lift coefficient of the airfoil 0021 with tubercles was higher at Re = 1.2×105 and 1.69×105 in post critical region (at higher angle of attach) than airfoils without tubercles but this difference relatively diminished at higher Reynolds numbers and beyond indicating that there is no effect on the lift coefficients of airfoils with tubercles at higher Reynolds numbers whereas drag coefficient remains unchanged. It is noted that at Re = 1.69×105, the lift coefficient of airfoil without tubercles drops from 0.96 to 0.42 as the angle of attack increases from 15° to 20° which is about 56% and the corresponding values of lift coefficient for airfoil with tubercles are 0.86 and 0.7 at respective angles with18% drop.


2018 ◽  
Vol 72 ◽  
pp. 01007 ◽  
Author(s):  
Faizan Afzal ◽  
Muhammad S. Virk

This paper describes a brief overview of main issues related to atmospheric ice accretion on wind turbines installed in cold climate region. Icing has significant effects on wind turbine performance particularly from aerodynamic and structural integrity perspective, as ice accumulates mainly on the leading edge of the blades that change its aerodynamic profile shape and effects its structural dynamics due to added mass effects of ice. This research aims to provide an overview and develop further understanding of the effects of atmospheric ice accretion on wind turbine blades. One of the operational challenges of the wind turbine blade operation in icing condition is also to overcome the process of ice shedding, which may happen due to vibrations or bending of the blades. Ice shedding is dangerous phenomenon, hazardous for equipment and personnel in the immediate area.


2020 ◽  
Vol 5 (3) ◽  
pp. 977-981 ◽  
Author(s):  
Anna-Maria Tilg ◽  
Charlotte Bay Hasager ◽  
Hans-Jürgen Kirtzel ◽  
Poul Hummelshøj

Abstract. Leading-edge erosion (LEE) of wind turbine blades is caused by the impact of hydrometeors, which appear in a solid or liquid phase. A reduction in the wind turbine blades' tip speed during defined precipitation events can mitigate LEE. To apply such an erosion-safe mode, a precipitation nowcast is required. Theoretical considerations indicate that the time a raindrop needs to fall to the ground is sufficient to reduce the tip speed. Furthermore, it is described that a compact, vertically pointing radar that measures rain at different heights with a sufficiently high spatio-temporal resolution can nowcast rain for an erosion-safe mode.


Author(s):  
Yan Wang ◽  
Liang Wang ◽  
Chenglin Duan ◽  
Jian Zheng ◽  
Zhe Liu ◽  
...  

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