Ship cabin ventilation systems face high inlet noise, limited allowable pressure drop, and constrained axial space. This study proposes an innovative Wedge-Disc silencer incorporating annular sound-absorbing wedges. The manufactured silencer achieves an insertion loss of up to 17 dB within a compact axial length of 418 mm, with a drag coefficient of only 0.22. A hybrid acoustic model combining Mechel, micro-perforated panel (MPP), and Johnson-Champoux-Allard (JCA) theories is developed and validated for the three-layer wedge structure. Parametric analysis reveals that the perforation ratio has a negligible effect on the silencer’s low-frequency performance. Maintaining a conical lower wedge with sufficient height is crucial for low-frequency absorption; each 100 mm increase in upper wedge length raises the insertion loss by 2.6 dB across the frequency spectrum, and increasing the number of upper wedges provides the most significant enhancement to low-frequency attenuation.
Lin et al. (Thu,) studied this question.