Abstract
This paper shows the pressure distribution at the 50%radial section of a rotor blade of 10m-diameter wind turbine in yawed operation. The pressure sensors were mounted on the blade, and local inflow angle and local dynamic pressure were measured with the use of five hole Pitot tubes at 1 chord length upwind of the blade leading edge. It was found that the normal force coefficient in yawed condition decreases compared to that for non-yawed condition. Even if local angle of attack and the relative inflow velocity are the same, pressure distribution shows differences due to the local slip angle. The tufts flow-visualization on the rotating blade was carried out by setting a video camera on the rotating system. Separation in the region of middle chord to trailing edge on suction surface is thought to be the main reason of the reduction of normal force coefficients.
