高速铁路主动降噪声屏障次级声源位置研究

Research on the Secondary Sound Source Position of Active Noise Barrier on High-speed Railway

采用主动降噪技术提高传统直立式高速铁路声屏障对中低频段噪声的降噪效果,需要研究主动降噪系统中次级声源的合理位置。根据波动声学的声绕射理论,结合对不同高度声源的声绕射仿真结果,确定绕射声的"虚拟声源"范围,并将次级声源设置在该范围内开展主动降噪仿真分析。结果表明,在频率低于800 Hz时,次级声源对声影区的较大范围内可以取得明显的降噪效果。

To improve the noise reduction effect of traditional vertical high-speed railway noise barrier in the low and medium frequency band by use of active noise cancellation technology, the optimal position of the secondary sound source in the active noise cancellation system should be studied. Based on the diffraction theory of wave acoustics and the barrier’s diffraction simulation results of sound sources at different heights, the range of “virtual sound source” of diffraction sound wave was determined. Then the barrier’s active noise cancellation simulation analysis was carried out by setting the secondary sound source in the range. The results revealed that when the frequencies were below 800 Hz, the secondary sound source brought significant noise reduction in the most range of the acoustic shadow area.