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Kim, Sang-Ryul;Kim, Hyun-Sil;Lee, Sung-Hyun;Park, Geun-Hyo
- Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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- 2012.04a
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- pp.600-605
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- 2012
In this paper, the acoustic performance of a shipboard large-sized room unit is studied. The room unit is a kind of rectangular absorptive chamber with a partition whose surface absorptive material with fabric skin is attached to. The room unit has one inlet and three outlet. At the inlet, a plane damper is installed to control the flow rate. The acoustic performance of a prototype room unit is measured using a HVAC mock-up. It is shown that its insertion loss is comparable with that of a commercially-used room unit but the developed room unit generates flow noise higher than the other one. The major source of flow noise is analyzed by NADS-R, the noise analysis program for room unit. Cone-shaped dampers are proposed to be used as the damper of a room unit to reduce flow noise. It is shown that the cone-shaped damper decrease flow noise remarkably.
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Kim, Sang-Ryul;Kim, Hyun-Sil;Lee, Sung-Hyun;Park, Keun-Hyo
- Transactions of the Korean Society for Noise and Vibration Engineering
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- v.22 no.5
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- pp.468-473
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- 2012
In this paper, the acoustic performance of a shipboard large-sized room unit is studied. The room unit is a kind of rectangular absorptive chamber with a partition whose surface absorptive material with fabric skin is attached to. The room unit has one inlet and three outlets. At the inlet, a plane damper is installed to control the flow rate. The acoustic performance of a prototype room unit is measured using a HVAC mock-up. It is shown that its insertion loss is comparable with that of a commercially-used room unit but the developed room unit generates flow noise higher than the other one. The major source of flow noise is analyzed by NADS-R, the noise analysis program for room unit. Cone-shaped dampers are proposed to be used as the damper of a room unit to reduce flow noise. It is shown that the cone-shaped damper decrease flow noise remarkably.
https://doi.org/10.5050/KSNVE.2012.22.5.468 인용 PDF KSCI

Lee, Hyun-Yup;Shin, Su-Yong;Chung, Jung-Hoon;Kwak, Jeong-Seok;Lew, Jae-Moon
- Journal of the Society of Naval Architects of Korea
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- v.46 no.2
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- pp.165-170
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- 2009
Most of the naval shipboard equipments strongly require isolation devices to keep their performance and durability from severe noise and vibration loading. The rubber mount is well-known as one of most effective way to isolate major equipments from noise and vibration. The performance of the rubber mount is determined by characteristics of shock stiffness and vibration stiffness and the frequency range of interest is up to several Kilo Hz in navy vessels. In this study, an vibration experiment method for the rubber mount has been developed as a foundation work for assessing dynamic stiffness up to high frequency. Also experiments for a typical rubber mount has been carried out and the results has been discussed.
https://doi.org/10.3744/SNAK.2009.46.2.165 인용 PDF KSCI

Hyun-Ju Kang;Jae-Seung Kim
- Journal of the Society of Naval Architects of Korea
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- v.29 no.1
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- pp.113-122
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- 1992
When predicting shipboard noise levees, the accuracy depends largely on the value of the structureborne noise transmission loss. Although empirical formulars are frequently used because of their simplicities, researches on the analytical methods to estimate the transmission loss of structureborne noise such as wave guide theory and SEA has long bean one of the major topics in shipboard acoustics to overcome the inherent limiations of empirical ones. This paper describes an application of SEA to predict the transmission loss of the structureborne noise of a simple shiplike structural mode1 consisted of 22 flats plates. The result shows trial discrepancies between experimental and theoretical transmission losses are less than 3 dB.
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