材料期刊网

采用泡沫铝材料对柴油发电机的混合频率噪音进行隔音处理，分析了发电机噪声的频谱特点，将不同孔结构、不同厚度、不同复合方式的泡沫铝材料应用于发电机外壳，并比较了隔音效果。研究结果表明，泡沫铝材料对于发动机的混合型噪音，在高频段有明显的隔音效果，而在低频段隔音效果不明显。闭孔泡沫铝在大于500 Hz的高频段的隔音效果比开孔的好，而在63~125 Hz 的低频段，开孔泡沫铝的隔音效果好。泡沫铝与钢板复合后，对于低频噪声隔音效果有明显的作用。保持泡沫铝与钢板间一定的空腔距离，隔音频率段明显降低。20 mm 厚度的闭孔泡沫铝与钢板复合并保持20 mm 的空腔距离，可降低10~20 dB的噪音。

In this paper,the noise reduction (insulation)of diesel generators was dealt with by taking the advan-tages of aluminum foam for the mixed frequency band noise of generators.In this study,the spectrum proper-ties of generators were analyzed,and aluminum foam was applied with different pore structures,thickness and combination to the housing of a generator,and the comparison was made here with the results of sound insula-tion for generator.The results showed that when aluminum foam was employed for insulation of mixed noise from generator,it was highly effective for high frequency noise,but it was not obvious for low frequency noise. The effect of noise reduction was good when using closed-cell aluminum foam for frequency higher than 500 Hz;but opened-cell aluminum foam showed more effective in noise reduction for low frequency between 63-125 Hz. The combination of aluminum foam and steel plate shows very effective in noise insulation of low band frequen-cy.Maintaining a certain distance between steel plate and aluminum foam,noise reduction effect was obvious, and noise frequency band could also be reduced significantly.Keeping the distance of 20 mm between steel plate and closed-cell aluminum foam with 20 mm in thickness would reduce about 10-20 dB noise.