亚声速矩形射流的噪声辐射特性和声源分布

基于射流噪声模拟试验台，对出口面积相同的圆形喷口及宽高比分别为1、1.5、2、10的矩形喷口亚声速射流的远场噪声辐射特性和噪声源分布位置进行了较为系统的研究。通过远场噪声测量，获得了不同宽高比矩形喷口在不同方位角平面的射流噪声频谱分布结果相对于圆形射流的差异，揭示了矩形射流潜在的降噪潜力。通过基于波束成形算法的传声器阵列，得到了矩形射流噪声源峰值位置随频率的变化情况，系统分析了射流速度、方位角、宽高比等参数对矩形射流噪声源分布的影响。射流速度和方位角对矩形射流噪声源分布的归一化结果影响很小，而宽高比对矩形射流噪声源分布有较大影响：随着矩形宽高比的增加，矩形射流低频段噪声源向上游偏移，高频段噪声源向下游偏移。

Noise radiation characteristics and source distribution of subsonic rectangular jet

The far-field radiation characteristic and the noise source distribution of rectangular jet with aspect ratios 1, 1.5, 2, 10 are measured based on the jet noise simulator and the results are analyzed. The differences of the far-field noise frequency spectrum at specified azimuth plane between the round jet and the rectangular jet with different aspect ratios are presented, which shows the noise reduction potential of the rectangular nozzles. The changing of jet noise peak location with frequency of rectangular jet is obtained through the microphone array with beamforming algorithm. The influences of jet velocity, azimuth angle, and aspect ratio on the rectangular jet noise source distribution are systematically analyzed. The jet velocity and azimuth angle have little effect on the normalized jet noise source distribution, whereas the aspect ratio has a large impact. With the increase of the aspect ratio, the low frequency noise peak of rectangular jet moves upstream, and the high frequency noise peak moves downstream.