Acoustical performance of ventilated aluminum T-slot columns-based sonic cage

Abstract

This study demonstrates a modular, compact, and lightweight sonic cage for sound mitigation applications. The design prototype utilized the principle of sonic crystals and has been composed of periodically arranged readily available aluminum extrusion T-slot columns. The preliminary design has demonstrated a sound insertion loss peak of 2.94 dB at 2000 Hz, while a broad insertion loss spectrum has been obtained in 630–1000 Hz. Additionally, to improve the low-frequency performance, two additional design strategies utilizing the characteristics of T-slots have been proposed. The experimental results have revealed the significant improvement of sound insertion loss peak values in low-to-mid frequency. With design strategy I, an insertion loss peak value of 10.2 dB was observed at 500 Hz, while with design strategy II, two significant insertion loss peaks of 7.26 dB and 10.33 dB were observed at 800 Hz and 2000 Hz. Moreover, the proposed designs have revealed the tunable insertion loss peaks frequency. The designed insertion loss peaks demonstrated the feasibility of the sonic cage concept for mitigating the noise sources.