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Enclosure Noise Source Evaluation Based on Beamforming and Transfer Path Analysis

CHENG Jian;SUN Jie;LIU Bin;HUANG Zhen-yu

2011, 31 (4): 119-124. DOI: 10.3969/j.issn.1006-1355-2011.04.028

Abstract （1745）

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Noise source evaluation for enclosure noise control is a difficult problem due to the large amount of noise sources involved in the complicated acoustic field. In this paper, an enclosure noise source evaluation method is presented. This method mainly includes four steps: (1) dividing the enclosure space into several sub-spaces according to the potential source positions; (2) applying the beamforming method in terms of the measured A-weighting sound pressure level in each sub-space to find the significant sources;(3) computing the contribution of each significant source to the target position by the transfer path analysis (TPA), and (4) employing an error analysis of the calculated noise to verify the noise evaluation. The simulation results show that this approach can reduce the reverberation influence and TPA work. Therefore, it is a good approach for the evaluation of the enclosure noise sources

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《Experimental Modal Analysis of a Refrigeration Compressor’s Shell》

GUO Wei;LIU Bin;FENG Tao;ZHANG Yi

2010, 30 (3): 67-70. DOI: 10.3969/j.issn.1006-1355.2010.03.018

Abstract （2307）

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By using hammering pulseinspirit method, the experimental modal analysis of a refrigeration compressors shell is carried out. The fundamental modal parameters, including natural frequencies (1kHz 4kHz), damping and mode shapes, are estimated and identified. The intrinsic vibration characteristic of the compressors shell is obtained. Based on the experimental modal analysis, the dynamic characteristic of the shell structure is investigated. The results show that the main modal shapes of the compressors shell are essentially the outwardexpanding and inwardcontracting vibrations. The main cause of noise radiation is the intrinsic vibration of the shell. The results of the experimental modal analysis can provide a useful reference for vibration and noise reduction of the compressors.

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《ODS & Low-frequency Noise Analysis on the Tilt Open Drum Washing Machine》

LIU Bin;FENG Tao;WU Xue;HUANG Zhi-gang;ZHU Teng-fei

2010, 30 (3): 50-54. DOI: 10.3969/j.issn.1006-1355.2010.03.014

Abstract （3684）

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By using operational deflection shapes (ODS) technology, the vibration of a tilt open drum washing machine （7-600Hz）during dehydration was investigated. Combining with the noise measurement results, the correlation between vibration and noise during dehydration was preliminary discussed. It showed that, the vibration of the machine excited by the unbalance force of the running parts and the electromagnetic force of the electromotor, and the lowfrequency noise was closely related to the vibration. The noise level of both left and right sides were higher than front and back sides. To decrease the noise level, it can modify the frequencyresponse of the machine.

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《Study on Test Method of Transmission Loss of Vehicle Muffler》

MA Jia-yi;YUAN Zhao-cheng;YU Ying-xiao;LIU Bin-chun

2009, 29 (6): 161-164. DOI: 10.3969/j.issn.1006-1355.2009.06.161

Abstract （3416）

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The transmission loss is one of the important characteristics to appraises the muffler performance. But in the experiment, it should been pay attention to the acoustic source stability and sound wave reflection questions.In this article summarized some differences which the insertion loses and transmits loses, Simultaneously pointed out the merits of application transmission loss test noise elimination performance，And for avoided the sound reflection proposed one new transmission loss test way. Discussed the transmission loss value change situation when the muffler be inputed different intensity sound pressure, which through the massive experiments.

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