Research on sound absorption characteristics of corrugated perforated plate

The dissipative effect of corrugated perforated plate on acoustic wave is studied in two cases of plane wave vertical incidence and grazing incidence in this paper. The results show that the acoustic performance of the corrugated perforated plate in both cases is different from that of the flat perforated plate. Under the condition of vertical incidence, the equivalent perforation rate can make the sound absorption coefficients of the corrugated perforated plate and the flat perforated plate coincide in the range of medium and low frequencies, but the corrugated perforated plate will have a double peak phenomenon that is different from the flat perforated plate at high frequencies. Further study reveals that it is due to the continuous change of the depth of the back cavity caused by the shape of the corrugated plate. Under the condition of grazing incidence, the corrugated perforated plate and flat perforated plate cannot be replaced by the equivalent perforation rate. The height and length of the corrugated perforated plate have obvious effects on its acoustic performance. When the angle of the corrugated plate is constant (the tangent angle corresponding to the plate height and a quarter of the plate length), the corrugated perforated plate with the plate length less than 75 mm has similar acoustic performance.