Parametric research on influence of trailing edge's thickness to aerodynamic performance for wind turbine airfoils

This influence of trailing edge's thickness on aerodynamic performance for large wind turbine airfoils was studied. The trailing edge's thickness of NREL wind turbine airfoils S814 and S827 with test data was numerically treated with XFOIL. The trailing edge's thickness changes between 0.5% and 5.0% relative to chord with constant maximum thickness, camber and chord. The results indicate that when trailing edge's thickness increases within certain range, lift coefficient and drag coefficient also increase, but lift-drag ratio increases and then decreases. Lift coefficient and lift-drag ratio of airfoils reach to the best conditions when trailing edge's thickness is around 1.5% relative to chord. The conclusion can be used to design the wind turbine blades.