汽车消声器的声学性能分析与结构优化

针对某三缸发动机排气噪声超出目标限值,将声学性能作为评价指标,利用Virtual.Lab声学有限元模块对排气消声器的声学性能进行仿真分析,对比传递损失试验结果对该声学软件的仿真精度作出评价:Virtual.Lab软件在整个频段与试验值较为接近,能准确的反映消声器的声学性能。根据原排气消声器的传递损失分析结果,提出亥姆霍兹共振腔结构及阻抗复合型结构等参数设计的前后端消声器优化方案。最终对优化后的排气消声器进行尾管噪声试验,确认排气噪声达标。

Acoustic Performance Analysis and Optimized Design of Vehicle Muffler

Based on a three-cylinder engine exhaust noise exceeding target limit,according to the evaluation index of acoustic performance,the analysis of acoustic performance was conducted in acoustic FEM module of software Virtual.Comparing the transmission loss test results to evaluate the simulation accuracy of the acoustic software:the simulation results of Virtual.Lab software were close to the experimental value on entire frequency band and accurately reflection on the acoustic performance of the muffler.The simulation results are compared with the test results to confirm the simulation accuracy.According to the analysis results of the transmission loss of the original exhaust muffler,optimization solutions for front and rear mufflers designed with parameters such as Helmholtz resonator and impedance compound structure was proposed for the frequency band with poor muffling effect.Finally,the tail pipe noise test was performed on the optimized exhaust muffler to confirm that the exhaust noise reached the standard.