单极子声源平面空间有源降噪的最短距离

The Shortest Distance of Monopole Noise Sources in Plat Space under Active Noise Control

以单极子噪声源与单极子抗噪声源组成的声场为研究对象,得出用单极子抗噪声源控制单极子噪声源,使两声源所在的平面空间内的总声功率最小时两声源本身的声强的关系。并计算空间内任意一点的径向平均有功声强。得出最小径向平均有功声强与声源的频率和两声源的距离有关,在一定频率下,两声源距离越近,控制后的径向平均有功声强越小,距离一定的情况下,频率越小,径向平均有功声强越小。通过仿真实验进行验证,并最终得到某些低频噪声达到全空间消声时噪声源与抗噪声源的最短距离。

This article studies the sound fields of the monopole noise source and monopole anti-noise source. The relationship between the sound intensity of the noise source and the sound intensity of the anti-noise source under the condition of the least sound power in the plat sound field is obtained. In addition, the radial average active sound intensity at any point in the sound field is calculated, which is found to be related to the frequency of the sound source and the distance between the two sources. For a fixed frequency, the radial average active sound intensity decreases with the distance between the two sources increasing after the control. For the fixed distance between the two sources, the radial average active sound intensity decreases with the frequency decreasing after the control. Through the MATLAB simulation, the shortest distance between the noise source and anti-noise source when the sound intensities of some low-frequency noises in the whole space vanish is obtained.