한국음향학회지 (The Journal of the Acoustical Society of Korea)

  • 제40권4호
  • /
  • Pages.320-329
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  • 2021
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  • 1225-4428(pISSN)
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  • 2287-3775(eISSN)
한국음향학회 (The Acoustical Society of Korea)
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에어마스커의 기포크기 추정 경험적 모델

An empirical model of air bubble size for the application to air masker

  • 박철수 (한국해양과학기술원 부설 선박해양플랜트연구소) ;
  • 정소원 (한국해양과학기술원 부설 선박해양플랜트연구소) ;
  • 김건도 (한국해양과학기술원 부설 선박해양플랜트연구소) ;
  • 박영하 (한국해양과학기술원 부설 선박해양플랜트연구소) ;
  • 문일성 (한국해양과학기술원 부설 선박해양플랜트연구소) ;
  • 임근태 (한국해양과학기술원 부설 선박해양플랜트연구소)
  • 투고 : 2021.05.11
  • 심사 : 2021.06.29
  • 발행 : 2021.07.31
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⟨ 이전 논문 다음 논문 ⟩

초록

본 논문에서는 선박 수중방사소음 저감을 위한 에어마스커의 기포크기 추정 모델을 제시하였다. 제시된 모델은 Rayleigh의 제트 불안정 모델과 연속 조건을 이용하여 유도된 기존 모델에 공기의 제트유속을 도입함으로써 저속유동 조건에서 발산하는 단점을 보완 하였다. 공기의 제트유속은 유동이 없는 경우 기포의 크기를 이용하여 추정하였다. 유동이 없는 매질에서 기포의 크기는 분사된 공기의 레이놀즈수를 기반으로 층류구간, 천이구간, 그리고 난류구간으로 나누어 경험적 방법으로 추정 하였다. 제시된 기포크기 추정 모델은 Computational Fluid Dynamics(CFD) 해석결과 그리고 기존 문헌의 실험결과와 비교하여 잘 일치함을 확인하였다. 끝으로, 음향 역산법을 활용하여 대형터널에서 수행된 에어마스커 공기분사 실험의 계측된 삽입손실로부터 기포의 분포를 추정하였다. 역산된 기포분포와 기포크기 추정 모델의 추정 결과를 비교하였다.

In this paper, an empirical model of air bubble size to be applied to an air masker for reduction of underwater radiation noise is presented. The proposed model improves the divergence problem under the low-speed flow condition of the existing model derived using Rayleigh's jet instability model and simple continuity condition by introducing a jet flow velocity of air. The jet flow velocity of air is estimated using the bubble size where the liquid is quiescent. In a medium without flow, the size of the bubble is estimated by an empirical method where bubble formation regime is divided into a laminar-flow range, a transition range, and a turbulent-flow range based on the Reynolds number of the injected air. The proposed bubble size model is confirmed to be in good agreement with the Computational Fluid Dynamics (CFD) analysis result and the experimental results of the existing literature. Using the acoustic inversion method, the air bubble population is estimated from the insertion loss measured during the air injection experiment of the air- masker model in a large cavitation tunnel. The results of the experiments and the bubble size model are compared in the paper.

키워드

과제정보

본 논문은 선박해양플랜트연구소의 주요사업인 "에어버블마스킹을 이용한 선박 수중방사소음 저감원천기술 개발"(PES3900)의 지원에 의해 수행되었다. CFD 데이터를 제공해 주신 동의대학교 박일룡 교수님께 감사드린다.

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