The acoustics of shrieking perforated panels

Abstract

Under windy conditions, vortex shedding can cause perforated metal skins to emit undesirable noise. This phenomenon was observed, measured, and replicated. The acoustic spectrum was analyzed and compared to the modes of a vibrating plate. An extensional-damping layer was added to the plates for vibration isolation. The damping layer was applied as a high-loss painted coating to the surface of the plates. The acoustic spectrum was then analyzed again and compared to the spectrum without treatment. This study describes the process used to investigate and solve this noise control problem.