Influence of the modification of asymmetric trailing-edge thickness on the aerodynamic performance of a wind turbine airfoil

Abstract

In this paper, the influences of trailing thickness and asymmetric modification factor on the aerodynamic performance were studied using the commercial numerical simulation package FLUENT®. In addition, three methods were used to minimize the drag coefficient, including affixing a zigzag trailing-edge on the trailing edge of the airfoil, a slotted airfoil, and a combination of the zigzag method and the slotted airfoil. The results showed that the trailing thickness and the asymmetric modification factor significantly affected the aerodynamic performance of the airfoil. Meanwhile, the results from the three drag-reducing methods showed that affixing a zigzag trailing-edge reduced the airfoil drag at the expense of a certain amount of lift coefficient at low angle of attacks (AOAs). Furthermore, the use of slotted airfoil produced both the increase in lift coefficient and the decrease in drag coefficient at high AOAs. The use of the combination of zigzag trailing-edge and the slotted airfoil not only reduced the increase in drag caused by the slotted airfoil at low AOAs and by the zigzag trailing-edge at high AOAs, but also reduced the decrease in lift coefficient, which was caused by the zigzag trailing-edge.