Experimental study on the near wake recovery of horizontal axis wind turbines with blades of different trailing edge thickness

Based on the traditional sharp trailing edge airfoil, on the research that the rational change of trailing edge thickness of airfoil can improve the lift-drag ratio, this paper uses the method of symmetrical thickening of the trailing edge to trailing edge thickness of the airfoils at various parts of the small horizontal axis wind turbine blades independently designed using the NACA4415 airfoil. After scaling down, the blades are fabricated for wind tunnel tests. The experiment shows that compared with the sharp trailing edge blades, in the region at the same position where x/R = 2–4, the wake expansion and the change in turbulence intensity of the blade with a trailing edge thickness of 3%c are the most significant. The expansion ratio is approximately 3.3%, and the turbulence intensity is reduced by about 3% compared to that of the original blade. At the position where x/R = 4, the turbulence intensity is reduced by about 2.5% compared to that of the original blade. When tip speed ratio (TSR) = 5, the rotor power of the blade with 3%c trailing edge thickness has the maximum increase, which is 7.01% compared with the original blade. The blade with changed trailing edge thickness has more significant power generation efficiency when the TSR is high and can adapt to harsher environments in wind farms.