基于切向流效应的宽频带穿孔板声衬的研究

Broadband sound-absorption of perforated lining in the presence of grazing flow

对于大孔径穿孔板,减小声质量是实现宽带吸声的关键,而切向流效应可以提高穿孔板声阻、减小声质量,从而实现大孔径穿孔板宽频带吸声.基于上述结论,提出了切向流条件下穿孔板声衬参数的设计原则,并设计了穿孔板消声器实验,实验结果表明:对于大孔径穿孔板,低声质量的通流声衬吸声频带明显宽于无流条件的声衬.这种声衬在航空发动机消声短舱、汽车发动机进排气管道、各种通风管道等存在较大气流环境的消声具有实际意义.

For large aperture perforation plate,reducing acoustic mass is a way to realize broadband sound absorption.Meanwhile,the acoustic resistance can be enlarged due to the grazing flow effect as well as the reduction of the acoustic mass.Based on above results,the designing principle was proposed for the parameters of the perforation plate.Besides this,the perforated plate muffler experiment was also conducted.The experimental results show that broadband sound absorption can be achieved for large aperture perforation plate with low acoustic mass in the presence of grazing flow when compared with that of perforated lining without grazing flow.Such perforation plate can be applied to the noise reduction of the aircraft engine nacelle,inlet and exhaust pipe of motor engine,and all kinds of ventilation pipe with large air flow.