Surface pressure measurements on the blade of an operating Mod-2 wind turbine with and without vortex generators

Pressure measurements covering a range of wind velocities were made at one span location on the surface of an operating Mod-2, 2500 kW, wind turbine blade. The data, which were taken with and without vortex generators installed on the leading edge, show the existence of higher pressure coefficients than would be expected from two-dimensional wind tunnel data. These high pressure ratios may be the result of three-dimensional flow over the blade, which delays flow separation. Data are presented showing the repetitiveness of abrupt changes in the pressure distribution that occur as the blade rotates. Calculated values of suction and flap coefficients are also presented.