The Journal of the Acoustical Society of Korea (한국음향학회지)

The Acoustical Society of Korea (한국음향학회)
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Insertion loss by bubble layer surrounding a spherical elastic shell submerged in water

수중의 구형 탄성 몰수체를 둘러싼 기포층에 의한 삽입손실

  • Received : 2022.01.25
  • Accepted : 2022.03.17
  • Published : 2022.03.31
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Abstract

Acoustic radiation from a submerged elastic shell with an internal fluid surrounded by the bubble layer is studied with the modal theory. An omni-directional point source located on the center of the internal fluid is used as acoustic noise source. The unknown coefficients of modal solutions are solved using the interface conditions between media. To preserve the stability of the modal solution over wide frequency ranges, the scaled technique of modal solution is used. The bubble layer is modeled with four kinds of bubble distribution; uni-modal distribution, uniform distribution, normal distribution, and power-law distribution, based on the effective medium theory of Commander and Prosperetti. For each bubble distribution, the insertion losses are mainly calculated for the frequency. In addition, the numerical simulations are performed depending in the bubble void fraction, the material property of elastic shell, and the gap between the bubble layer and the elastic shell.

본 논문에서는 내부 유체를 갖는 수중에 몰수된 탄성 쉘이 기포층으로 둘러싸여 있을 때의 음향 방사를 모드 이론을 이용해 연구했다. 전 방향성의 점음원이 내부 유체의 중심에 위치해 있고 음향 소음원으로서 사용되었다. 모드 해의 미지수는 매질 사이의 경계조건으로부터 계산된다. 넓은 주파수 대역에서 모드 해의 안정성을 유지하기 위해, 모드 해의 규격 기법이 사용되었다. 기포 층은 Commander와 Prosperetti의 유효 매질 이론에 기반하여, 단일 모드 분포, 균일 분포, 정규 분포, 멱함수 분포를 이용해 각각 모의되었다. 각각의 기포 분포에 대해 삽입손실이 주파수에 대해 계산되었다. 추가적으로 공극비, 탄성 쉘의 매질 특성, 탄성 쉘과 기포층의 간극의 영향에 대한 수치해석을 수행했다.

Keywords

Acknowledgement

본 논문은 한국해양플랜트연구소의 "다중산란 기포층 해석모델 및 마스킹 연구용역"과 해양수산부의 "인공지능을 이용한 하이브리드 음전달 모델 선박 수중방사소음 분석 프로그램 개발"의 연구 결과 중 일부이다.

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