Journal of the Korean Society of Marine Environment & Safety (해양환경안전학회지)

The Korean Society of Marine Environment and safety (해양환경안전학회)
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Computational Analysis on the Noise Characteristics of Ship Large Duct

선박용 대형 덕트의 소음 특성 전산해석 연구

  • Song, Jee-Hun (Department of Naval Architecture and Ocean Engineering, Chonnam National University) ;
  • Hong, Suk-Yoon (Department of Naval Architecture and Ocean Engineering, Seoul National University) ;
  • Lee, Yi-Soo (Department of Naval Architecture and Ocean Engineering, Seoul National University) ;
  • Kwon, Hyun-Wung (Department of Naval Architecture and Ocean Engineering, Koje College)
  • 송지훈 (전남대학교 조선해양공학전공) ;
  • 홍석윤 (서울대학교 조선해양공학과) ;
  • 이이수 (서울대학교 조선해양공학과) ;
  • 권현웅 (거제대학교 조선해양공학과)
  • Received : 2015.10.27
  • Accepted : 2015.12.28
  • Published : 2015.12.31
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Abstract

Noise prediction for HVAC(Heating, Ventilating and Air Conditioning) systems are normally performed by empirical method suggested by NEBB(National Environmental Balancing Bureau, 1994). However, the method is not suitable for large ducts in ships. In this paper, computational analysis methods are used to develop a noise prediction method for the large ducts in ships. To develop regression formula of attenuation of sound pressure level in large ducts, Boundary Element Method(BEM) is used. BEM and Computational Fluid Dynamics(CFD) are applied to the analysis of flow-induced noise in ducts with stiffeners inside. Loud noise above 100 dB can be generated in some cases. Breakout noises of large ducts are also analyzed by using BEM and Finite Element Method(FEM). The acoustic pressure level shows about 10-15dB difference between inside and outside of the duct. Utilizing the results of this study, it is expected that shipyard planners can predict noise of the HVAC system for ships.

공조시스템의 소음 예측은 주로 NEBB에서 제안한 경험적인 방법에 의해 수행된다. 그러나, NEBB에서 제안한 방법은 선박에만 있는 대형 덕트의 요소를 반영하지 못하므로 선박에 적용하는데 한계가 있다. 본 논문에서는 선박용 대형 덕트의 소음 예측을 위한 전산해석방법을 연구하였다. 경계요소법을 사용하여 대형 덕트의 단위 길이당 소음 감소량에 대한 추정식을 개발하였고, 경계요소법과 전산유체역학을 사용하여 보강재가 설치된 대형 덕트에서의 유동기인소음을 예측하였다. 유입 유속이 10m/s, 보강재의 종류가 200플랫 바인 경우 100 dB 이상의 큰 소음이 발생하는 것을 알 수 있었다. 또한, 경계요소법과 유한요소법을 사용하여 덕트 투과 소음을 예측하였다. 덕트 내부와 외부의 음압 값 차이는 대략 10~15 dB정도 인 것을 알 수 있었다. 이를 통해 조선소에서는 대형 덕트를 포함한 선박 HVAC 소음 예측을 할 수 있을 것으로 기대한다.

Keywords

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