Acoustic Absorption Phenomena of Perforated Plate with Cross Flow

Abstract

The present paper focuses on the effect of flow velocity on acoustic absorption performance of perforated plate. We experimentally measured the flow velocity, acoustic pressure, and transfer function using the improved acoustic impedance tube. The normal incidence absorption coefficient was calculated from the measured transfer function using transfer function methods. As the flow velocity passing through the orifices increased, the peak level of the acoustic absorption coefficient increased. The acoustic absorption performance has improved using taper orifices of perforated plate. The peak frequency of the acoustic absorption coefficient depended on the taper angle of holes of perforated plate. We discussed the effect of the flow velocity and taper orifices on the specific acoustic impedance.