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

The Korean Society of Marine Environment and safety (해양환경안전학회)
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Flow-Induced Noise Prediction for Submarines

잠수함 형상의 유동소음 해석기법 연구

  • Yeo, Sang-Jae (Department of Naval Architecture and Ocean Engineering, Seoul National University) ;
  • Hong, Suk-Yoon (Department of Naval Architecture and Ocean Engineering, Seoul National University) ;
  • Song, Jee-Hun (Department of Naval Architecture and Ocean Engineering, Chonnam National University) ;
  • Kwon, Hyun-Wung (Department of Naval Architecture and Ocean Engineering, Koje College) ;
  • Seol, Hanshin (Korea Research Institute of Ships & Ocean Engineering)
  • 여상재 (서울대학교 조선해양공학과) ;
  • 홍석윤 (서울대학교 조선해양공학과) ;
  • 송지훈 (전남대학교 조선해양공학전공) ;
  • 권현웅 (거제대학교 조선해양공학과) ;
  • 설한신 (한국해양과학기술원 부설 선박해양플랜트연구소)
  • Received : 2018.11.08
  • Accepted : 2018.12.28
  • Published : 2018.12.31
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Abstract

Underwater noise radiated from submarines is directly related to the probability of being detected by the sonar of an enemy vessel. Therefore, minimizing the noise of a submarine is essential for improving survival outcomes. For modern submarines, as the speed and size of a submarine increase and noise reduction technology is developed, interest in flow noise around the hull has been increasing. In this study, a noise analysis technique was developed to predict flow noise generated around a submarine shape considering the free surface effect. When a submarine is operated near a free surface, turbulence-induced noise due to the turbulence of the flow and bubble noise from breaking waves arise. First, to analyze the flow around a submarine, VOF-based incompressible two-phase flow analysis was performed to derive flow field data and the shape of the free surface around the submarine. Turbulence-induced noise was analyzed by applying permeable FW-H, which is an acoustic analogy technique. Bubble noise was derived through a noise model for breaking waves based on the turbulent kinetic energy distribution results obtained from the CFD results. The analysis method developed was verified by comparison with experimental results for a submarine model measured in a Large Cavitation Tunnel (LCT).

잠수함에서 발생하는 수중방사소음은 적함의 소나에 의해 피탐될 확률과 직결되며, 잠수함 저소음화 방안은 생존성 향상을 위해 필수적이다. 최신 잠수함의 경우 기계류 소음저감 및 고속/대형화가 진행됨에 따라 선체 주위에 발생하는 유동소음에 대한 관심이 높아지고 있다. 본 연구에서는 자유수면의 효과를 고려하여 잠수함 형상 주위에 발생하는 유동소음 수준을 예측할 수 있는 소음해석기법을 개발하였다. 잠수함이 자유수면 근처 운항시에 잠수함 주위 유동장의 교란에 의해 발생하는 난류유동소음과 쇄파버블에 의한 소음이 발생한다. 먼저 잠수함 주위 유동장 해석을 위해, VOF법 기반의 비압축성 이상유동(two-phase flow)해석을 수행하여 잠수함 주위 자유수면 형상과 유동장 정보를 도출하였다. 이후 난류유동소음해석을 위해 음향상사기법인 Permeable FW-H를 적용하였고, 쇄파버블 소음해석을 위해 유동해석에서 도출된 난류운동에너지 분포결과를 기반으로 쇄파버블 소음모델을 적용하였다. 최종적으로 개발된 유동소음 해석기법은 선박해양플랜트연구소(KRISO)의 대형캐비테이션터널(LCT)에서 수행된 잠수함 모형 유동소음계측 실험결과와 비교를 통해 검증을 수행하였다.

Keywords

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