汽车扩张式排气消声器传递损失仿真分析及优化

Simulation Analysis and Optimization of Transmission Loss of Expanding Automobile Exhaust Muffler

发动机排气噪声是影响汽车乘坐舒适度的一项重要指标。为研究排气消声器传递损失对其消声性能的影响规律,建立声学有限元模型计算消声器传递损失曲线,并在单级扩张腔消声器腔壁添加玻璃棉内衬对消声器进行优化。研究结果表明:单级扩张腔消声器随着频率增大声学性能越来越好,纵向共振会引起消声器传递损失曲线图的四个骤降,导致消声效果不佳。添加玻璃棉吸声内衬可提升单级扩张腔消声器消声效果,骤降依然存在,但总体频率越高衰减趋势变大。本文可为消声器声学性能提升设计提供理论指导。

Engine exhaust noise is an important indicator that affects the comfortability of a car.To study the influence of the transmission loss of the exhaust muffler on its silencing performance,an acoustic finite element model was established to calculate the transmission loss curve of the muffler,and a glass wool lining was added to the wall of the single-stage expanding cavity muffler for optimization.The research results show that the acoustic performance of the single-stage expanding cavity muffler is getting better and better as the frequency increases,and longitudinal resonance will cause four sharp drops in the transmission loss curve of the muffler,resulting in a poor silencing effect.The addition of sound-absorbing glass wool lining can improve the noise reduction effect of the single-stage expanding cavity muffler,while the sharp drops still exist,but the higher the overall frequency,the greater the attenuation trend.This article could provide theoretical guidance for the mufflers design to improve acoustic performance.