Aerodynamic Characteristics of Different Chord Length Wind Turbine Airfoil with Vortex Generators

In the inboard of blade of the large wind turbine, the air separation often occurs because of the thick aerofoil. Vortex generators (VGs) is an effective way to control the air separation. The DU97-W2-300 3D airfoil with the same vortex generators was researched with different chord of 0.6m, 1m and 1.5m. The transition model was used in numerical calculation. The results show that the transition model results had well agreement with test results. The mechanism of controlling flow separation with VGs was analyzed. For three different chord length, within 0°~14° attack angle, the results of lift coefficient were almost the same. When the attack angle is above 14°. With the augment of airfoil chord, the lift coefficient decreases and the region of flow separation of trailing edge increases gradually.