论文部分内容阅读
为了研究锯齿形尾缘对SD2030低雷诺数翼型尾缘噪声的影响,在普通室内,采用由31路麦克风组成的线性阵列对SD2030吹风试验进行了声学测量。实验过程中,基于机翼弦长的雷诺数范围为2.1×105~3.2×105。在考虑混响、驻波和壁面反射影响的基础上,设计了一长为1.72m的非等间距线性阵列。当频率大于1k Hz时,墙壁反射对测量结果的影响在0.5d B以内,驻波的影响也可以忽略。采用时域波束成形算法对声学信号进行处理之后,成功识别出了风洞噪声源、机翼前缘噪声源和尾缘噪声源。比较直尾缘机翼和锯齿形尾缘机翼的声源分布图发现,在1k~10k Hz的频率范围内,采用锯齿形尾缘设计能够降低尾缘噪声声压级最大约5d B。
In order to study the effect of the serrated trailing edge on the low Reynolds number airfoil tailwind noise of the SD2030, a linear array of 31 microphones was used for acoustic measurements of the SD2030 blowing test in a common room. During the experiment, the Reynolds number based on the chord of the airfoil ranges from 2.1 × 105 to 3.2 × 105. Based on the influence of reverberation, standing wave and wall reflection, a non-equidistant linear array with a length of 1.72m was designed. When the frequency is greater than 1k Hz, the influence of the wall reflection on the measurement result is within 0.5d B, and the effect of the standing wave is negligible. After processing the acoustic signal by using the time-domain beamforming algorithm, the wind tunnel noise source, the leading edge noise source and the trailing edge noise source are successfully identified. Comparing the sound source distribution of the straight-trailing wing and the serrated trailing edge wing, it is found that the serrated trailing edge design can reduce the maximum sound pressure level of the trailing edge edge to about 5d B in the frequency range from 1k to 10k Hz.