Effects of vortex generators on aerodynamic performance of thick wind turbine airfoils

The effects of vortex generators (VGs) on aerodynamic performance of thick wind turbine airfoils CAS-W2-350, CAS-W2-400, and CAS-W1-450 are presented. The measurements were carried out at a Reynolds number of 1 million with two experimental setups. Aerodynamic performance of testing models is obtained by measuring the surface pressure. The effects of height, chordwise position, and spanwise spacing between neighbor VGs are investigated, as well as the effect of a second row of VGs. The results show that the maximum lift coefficient increases with VGs installed towards the leading edge of airfoils but the lift at small angles of attack decreases when the chordwise position of VGs is smaller than 20% chord. The spanwise spacing between neighbor VGs has small effects on lift coefficient of CAS-W2-350, but strongly affects that of CAS-W2-400 before stall. The second row of VGs could further increase the lift coefficient at large angles of attack depending on the install positions and size of VGs.