塔架对风轮旋转过程中声场及流场的影响探究

基于压力脉动与声压之间的关系,利用Fluent数值模拟平台对风力机旋转过程中整机和单转子的声场和流场进行分析。对比2种模型的最大声压级位置,发现由于塔架的介入,整个模型的声场落后于流场约30°。分析塔旁y轴负向测点处压力脉动与声压级第1个峰值对应的方位角,结果发现在y/R=0.14、y/R=0.42、y/R=0.71与y/R=1时声压级（SPL）分别落后于压力脉动22°、5°、9°与18°。分析风力机旋转过程中两种模型塔附近监测点的声压级与压力脉动的变化趋势,结果表明：声压级振幅沿展向先增大后减小,在y/R=0.71处达到最大值;同样,在y/R=0.71时压力波动幅度最大。

STUDY ON INFLUENCE OF TOWER ON SOUND FIELD AND FLOW FIELD IN ROTATING PROCESS OF WIND TURBINE

Based on the relationship between pressure pulsation and sound pressure, Fluent numerical simulation platform was used to analyze the sound field and flow field of the whole wind turbine and single rotor in the process of wind turbine rotation. Comparing and analyzing the maximum sound energy positions of the two models, it is found that the acoustic field of the wind turbine is hysteresis to some extent to the flow field due to the interference of the tower, and the hysteresis angle is about 30°. The pressure pulsation in the negative direction of y-axis and the distribution of sound pressure level with rotor rotation azimuth are analyzed. Comparing the azimuth of the first peak, it is found that the SPL lags behind the pressure pulsation by 22°,5°,9°and 18° respectively at the positions of y/R=0.14,y/R=0.42,y/R=0.71 and y/R=1. The variation trend of sound pressure level and pressure pulsation at monitoring points near the two model towers during wind turbine rotation is analyzed. It is found that the amplitude of SPL increases first and then decreases as it moves from the root to the tip, and reaches the maximum at y/R=0.71. Similarly, the amplitude of pressure fluctuation reaches its maximum at y/R=0.71 and the slope of the peak and valley fluctuations is at its maximum.