Unsteady characteristics of pressure on wind turbine blade surface in the field

Field experiments are carried out to investigate the fluctuation characteristics of pressure on wind turbine blade surface in real operating environments. The tested wind turbine positioned pressure tapes along the blade span to obtain the dynamic pressure of seven airfoil sections over six rotation periods, and analyzed its time-domain, frequency domain, and standard deviation. The results show that the pressure on blade surface presents highly unsteady characteristics, and rotation of the wind turbine is one of the main factors that causes pressure fluctuations on the blade surface. The standard deviation of pressure near the leading edge of each airfoil section is relatively larger, indicating that the leading edge is the most sensitive to field wind conditions. Compared with the pressure surface, the blade suction surface contributes more to wind turbine power fluctuation and is more sensitive to various unsteady sources. Moreover, the standard deviation of the pressure on the blade pressure surface is largest at the tip, and the standard deviation of the pressure on the blade suction surface is clearly divided into two regions along the chord direction with different scales at different spanwise sections.