The Aerodynamic Performance of Horizontal Axis Wind Turbines under Rotation Condition

Abstract

The near-surface unsteady incoming flow in the atmospheric boundary layer has a great influence on the aerodynamic performance of horizontal axis wind turbines. To consider the effect of the rotation of the blade on the aerodynamic state of a wind turbine near the ground, the fluid-structure interaction (FSI) method based on the shear stress transfer (SST) turbulence model is applied to analyze the unsteady aerodynamic interaction characteristics including solving the velocity field, pressure field, structural response state, variation of deformation, and output power in the flow field of the wind turbine. The deformation fluctuation points of different blades in the upwind and downwind regions were observed to move towards the blade tips with increasing rotational speed. The variations of flow velocity and pressure that occur along the radial direction of the wind turbine are observed. The velocity increases from the root to the tip of the blade. The tower shadow effect causes the blade deformation in the upper and lower wind areas to fluctuate. It is more obvious when the blade overlaps with the tower; the overall displacement under the effect of rotation has a large increase compared with the shutdown. The peak increments reach 2.1437 mm to 0.8674 mm; under the effect of inter-action wind speed increased, wind turbine output power increased from 68.33 kW to 84.33 kW, respectively. It helps to better understand the aerodynamic performance of wind turbines, prolong the service life, and optimize the design.