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

  • 제25권6호
  • /
  • Pages.757-764
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  • 2019
  • /
  • 1229-3431(pISSN)
  • /
  • 2287-3341(eISSN)
해양환경안전학회 (The Korean Society of Marine Environment and safety)
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타원형 날개에 대한 공동소음 예측 연구

Study on Cavitation Noise Predictions for an Elliptic Wing

  • 정승진 (서울대학교 조선해양공학과) ;
  • 홍석윤 (서울대학교 조선해양공학과) ;
  • 송지훈 (전남대학교 조선해양공학전공) ;
  • 권현웅 (거제대학교 조선해양공학과) ;
  • 박일룡 (동의대학교 조선해양공학과) ;
  • 설한신 (한국해양과학기술원 부설 선박해양플랜트연구소) ;
  • 김민재 (국방과학연구소)
  • Jeong, Seung-Jin (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 Shipbuilding and Marine Engineering, Koje College) ;
  • Park, Il-Ryong (Department of Naval Architecture and Ocean Engineering, Dongeui University) ;
  • Seol, Han-Shin (Korea Research Institute of Ships & Ocean Engineering) ;
  • Kim, Min-Jae (Naval System R&D Institute, Agency for Defense Development)
  • 투고 : 2019.08.02
  • 심사 : 2019.10.28
  • 발행 : 2019.10.31
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초록

수중에서 빠른 속도로 운동하는 물체 주변에서 감압이 발생하며, 이로 인해 공동 핵이 팽창함으로써 캐비테이션이 발생한다. 캐비테이션이 발생하게 되면 소음 및 진동이 증가하며, 추진기의 경우 추진 성능이 저해되는 악영향을 초래하기 때문에 이에 대한 예측이 필요하다. 본 연구에서는, 캐비테이션 발생으로 인한 공동소음의 해석절차를 정립하고, 타원형 날개에 적용하였다. 먼저 전산유체역학해석을 수행하여, 날개 형상 주위 유동장 정보를 도출하였다. 공동 핵 밀도 함수를 활용하여, 핵의 초기 반경 별로 개수를 계산하였고 이들을 압력 강하가 큰 날개 끝 전류에 랜덤하게 배치하였다. 이후 공동소음 해석을 위해 각각의 핵에 대하여 Lagrangian 관점에서 버블 다이나믹스를 활용하였고, 계산된 공동의 거동으로부터 소음해석을 수행하였다. 공동소음은 광대역 소음의 특성을 가지는 것을 확인하였으며, 최종적으로 선박해양플랜트연구소(KRISO)의 대형캐비테이션터널(LCT)에서 수행된 실험 계측결과와의 비교를 통해 검증을 수행하였다.

Depressurization occurs around underwater objects moving at high speeds. This causes cavitation nuclei to expand, resulting in cavitation. Cavitation is accompanied by an increase in noise and vibration at the site, particularly in the case of thrusters, and this has a detrimental ef ect on propulsion performance. Therefore, predicting cavitation is necessary. In this study, an analytical method for cavitation noise is developed and applied to an elliptic wing. First, computational fluid dynamics are performed to obtain information about the flow fields around the wing. Then, through the cavitation nuclei density function, number of cavitation nuclei is calculated using the initial radius of the nuclei and nuclei are randomly placed in the upstream with large pressure drop around the wing tip. Bubble dynamics are then applied to each nucleus using a Lagrangian approach for noise analysis and to determine cavitation behavior. Cavitation noise is identified as having the characteristics of broadband noise. Verification of analytical method is performed by comparing experimental results derived from the large cavitation tunnel at the Korea Research Institute of Ships & Ocean Engineering.

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