초록
Low frequency exhaust noise of marine diesel engine is one of the most important noise sources in vessels. However, conventional absorptive silencers are ineffective to control exhaust noise because of low absorption in the low frequency range. In the paper, exhaust noise control of marine diesel engine was studied by using the hybrid silencer, which was composed of virtually divided array of concentric hole-cavity resonators and conventional absorptive silencer. A series of tests including field tests were performed to investigate the acoustic performance of the hybrid silencer. Consequently, its high performance of 5${\sim}$10 dB noise reduction in the low frequency range was confirmed and it is expected to be very helpful in reducing the exhaust noise of marine diesel engine.