【摘要】 采用改进的Johnson-Allard等效流体模型描述阻性消声器中吸声材料,通过LMS Virtual lab声学有限元分别研究材料的流阻率、孔隙率、形状因子、黏性及热特征长度对阻性消声器传递损失的影响。结果表明材料流阻率越大,两种特征长度越小,消声器传递损失越大;随材料形状因子增大,消声器传递损失曲线向低频段压缩,可根据目标噪声频域特性选择合适的形状因子;常规范围内,孔隙率对传递损失影响很小。这些结果为合理选择吸声材料、优化消声器消声性能提供了参考。更多还原

【Abstract】 A revised Johnson-Allard equivalent fluid model was adopted to describe sound absorbing material in dissipative silencers. The influence of material resistivity,porosity,tortuosity,viscous and thermal characteristic lengths on transfer loss( TL) of silencers were investigated through LMS Virtual lab acoustic FEA analysis respectively. Results show that silencer TL increases with larger material resistivity and smaller characteristic lengths,TL curves are compressed to the low-frequency side with larger tortuosity and porosity scarcely influences TL in its normal range,providing reference to proper material selection and performance improvement of dissipative silencers.更多还原