Research and development on active sound attenuated enclosure for generator set

摘要

The aim of this work is to design and implement a hybrid passive/active system to control the noise radiated by a generator sets. Passive control was afforded by a rectangular enclosure. Main wall panels of the enclosure were made of sound boarding. Air inlet and outlet were set for lowing temperature inside the enclosure. The multi-pass dissipative silencers were mounted in the inlet and outlet respectively, two-stage expansion chamber silencer was mounted for suppressing exhaust noise. The measured insertion loss was higher than 25 dB. Active control system was applied in order to suppress low-frequency noise from exhaust opening and outlet of the enclosure. The reference signal was supplied by a tachometer. High-temperature loudspeakers were used as control sources. The residual signal was picked up by microphones. Experimental results showed that the hybrid methods can achieve good performance. The results indicated that the proposed methods can efficiently improve the noise reduction of enclosure in generator set.