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对一款车用催化器的消声特性进行了试验测试和仿真研究。利用白噪声测试法获得其传声损失,基于GT-Power软件实现了对其声学性能的仿真分析。试验结果表明催化器具有明显的消声频段和通过噪声,峰值消声量可达到20dB;与催化器孔隙率相等的单管催化器模型传声损失曲线形状与试验结果接近,但消声量偏低;催化器载体的孔隙率以及管径、管数对传声损失有重要影响;双床催化器较单床催化器传声损失有较大提高,两级催化器较单级催化器传声损失也有很大的提高,消声特性改善明显。
The anechoic characteristics of a vehicle catalytic converter were tested and simulated. The acoustic loss was obtained by white noise test and the acoustic performance was simulated by GT-Power software. The experimental results show that the catalyst has obvious muffler frequency band and pass noise, and the peak muffling volume can reach 20dB. The shape of the sound transmission loss curve of a single tube catalyst model with the same porosity as the catalyst is close to the experimental result, but the muffling volume is low. The porosity of the catalyst support, as well as the diameter of the tube and the number of tubes, have an important influence on the transmission loss. The transmission loss of the dual-bed catalyst is much higher than that of the single-bed catalyst. The two- Greatly improved, obvious improvement of anechoic characteristics.