| The natural wind has the characteristics of paroxysmal, dynamic and non- uniformity. The disturbance of the wind on the horizontal axis wind turbine not only affects the output and its structure, but also has an important influence on the noise pollution. In this paper, based on wind tunnel experiments using ANSYS FLUENT load disturbance inflow function, combined IDDES(Improve Detached-eddy Simulation) turbulence model and acoustic FW-H equation for a horizontal axis wind turbine airfoil S flow field numerical simulation of sound field research, exploration and uniform inflow disturbance at the inflow of wind turbine rotating flow characteristics and acoustic radiation law, further analysis of the impact of turbulence intensity on wind turbine aerodynamic characteristics and noise。The results of numerical simulation show that compared with the uniform inlet flow perturbation in inflow wind wheel pressure surface is pressure gradient distribution of surface static pressure is slightly lower, the suction surface is larger by non-uniform wind and rotating inertia force。the pressure coefficient at the blade leading edge of the uniform inflow is greater than the disturbed inflow conditions, with the spanwise increasing pressure coefficient convergence. fluctuating pressure values are in the middle of the blade(0.57 R vicinity) maximum, at the blade root Min in two ways inflow, pressure peaks are same values with flow time but disturbance inflow are change. vorticity contours are displayed in a uniform inflow, 0.71 R blade at significant flow separation and vortex shedding blade trailing edge, the disturbance at the inflow is more intense at 0.57R; output power at rated tip speed ratio maximum and closest with experimental value, and when the tip speed ratio is less than the rated condition, power under the disturbance flow is more close to the experimental value, and beyond the rated condition the effect of the two kinds of input current on the power is small.The vortex motion of the incoming flow causes the tangential and normal disturbance and affects sound propagation. On the basis of the flow field analysis, further analysis of the wind wheel aerodynamic noise: The RMS value of the static pressure time derivative contours shows that the noise sources are located in the leading edge of the blade and consistent with the static pressure distribution by the rotating blades. Spectrum analysis points out two types of inflow acoustic energy mainly concentrated in low-frequency noise within the 500 hz, uniform inflow sound pressure level gradually decreases with increase of frequency, disturbance inflow resulting from the disturbance vortex frequency broadband noise increases with the frequency of new peak will appear. At 120 ° and 180 ° phase Angle of the sound pressure level of each section analysis,the spread of the noise with the distance from the sound source is far more strength is weak, uniform inflow sound propagation characteristics is law, and the disturbance inflow and experimental value in irregular beating phenomenon appeared in the process of spreading, and all in the axial distance of 10 cm to the sound pressure level drops fastest 50 cm, in agreement with the experimental value rule.On the influence of different inlet turbulence intensity of wind turbine analysis pointed out that when the turbulence intensity increased from 0.2% to 4%, the power was reduced by 5.07%, the test point noise increased 12.7 d B, the turbulence intensity increased to 10%, 11.35% lower power, test point sound pressure level increased by 19.86 d B.Finally, it is concluded that different inflow conditions on the wind turbine aerodynamic performance, the influence of noise propagation, etc and provide the basis for the wind turbine during use to achieve high performance, low noise, and provide a reference for the machine under study wind tunnel conditions. |
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