The Effect of Add-Ons on Wind Turbine Blades

Abstract

Add-ons improve power production and reduce noise on wind turbine blades. Appling vortex generators and Gurney flaps to inner part of blade increases lift force and increases power production with 0.3–3% more AEP. Design of vortex generators depends mainly on fin height, fin angle, chordwise location, shape of fin, and spacing between fin pairs. Design of Gurney flaps depends mainly on height. A winglet at the tip of the blade reduces tip-loss and increases power production with 0.5–1% more AEP. Design of winglet depends mainly on height of winglet and if it is an upwind or downwind pointing winglet. Serrated trailing edge applied at the outer part of the blade reduces trailing edge turbulence boundary layer noise with 2–3 dB. Design of winglet depends mainly on relative length of STE of airfoil chord, aspect ratio of tooth length, and the STE flap inclination to airfoil chord line.