DOI QR코드

DOI QR Code

Numerical analysis of acoustic radiation efficiency of plate structures with air bubble layers

기포층을 갖는 판 구조물의 음향 방사 효율에 관한 수치해석

  • Received : 2023.03.21
  • Accepted : 2023.05.02
  • Published : 2023.05.31

Abstract

Underwater noise pollution has a significant impact on the marine environment. This study proposed a simple approach to estimate the acoustic radiation efficiency of structures with air bubble layers. The method considered the insertion loss caused by the air bubble layer through post-processing of numerical results, assuming that insertion loss is equivalent to attenuation as demonstrated by previous studies. The proposed approach was validated by comparing it with a fully coupled analysis for plate structure models. The commercial finite element program COMSOL Multiphysics was used for the acoustic-structure interaction analysis, and the acoustic characteristics of air bubble layer for the fully coupled analysis was simulated by on the Commander and Prosperetti theory. The trends indicated good agreement between the simple approach and the fully coupled analysis in terms of radiation efficiency. It is confirmed that the proposed method is providing insight into the principal mechanism of underwater noise reduction for the bubble layer on the wedge-shaped structure.

수중 소음 공해는 해양 환경에 막대한 영향을 미친다. 본 연구에서는 기포층을 갖는 구조물의 음향 방사 효율을 추정하기 위한 간이 해석법을 제안하였다. 선행 연구 결과를 바탕으로 공기층에 의한 삽입 손실은 감쇠량과 동등하다고 가정하고, 기포층에 의한 삽입 손실은 수치해석 결과의 후처리 기법을 사용하여 계산되었다. 제안된 방법의 검증을 위해 판 구조물에 대한 음향-구조 완전 연성 해석을 수행하였다. 음향-구조 완전 연성 해석은 상용 유한 요소 프로그램 COMSOL Multiphysics를 사용하여 수행되었으며, 기포층의 음향 특성은 Commander 및 Prosperetti 이론을 사용하여 구현하였다. 음향 방사 효율 비교를 통해 간이 해석법과 완전 연성 해석 결과의 경향이 유사함을 확인하였다. 이러한 결과를 바탕으로 기포층을 갖는 쐐기 구조물의 방사 효율 메커니즘을 예측할 수 있음을 확인하였다.

Keywords

Acknowledgement

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2022R1G1A1003855).

References

  1. B. Wursig, C. R. Greene, and T. A. Jefferson, "Development of an air bubble curtain to reduce underwater noise of percussive piling," Mar. Environ. Res. 49, 79-93 (2000). https://doi.org/10.1016/S0141-1136(99)00050-1
  2. C. Park, S. W. Jeong, G. D. Kim, I. Moon, and G. Yim, "Acoustic insertion loss by a bubble layer for the application to air bubble curtain and air masker" (in Korean), J. Acoust. Soc. Kr. 39, 227-236 (2020).
  3. K. Lee, C. Lee, and C. Park, "Insertion loss by bubble layer surrounding a spherical elastic shell submerged in water" (in Korean), J. Acoust. Soc. Kr. 41, 174-183 (2022).
  4. S. J. Park, C. Park, K. Kim, J. Lee, K. Lee, and C. Lee, "Numerical investigation of acoustic radiation efficiency of a wedge-shaped structure surrounded by air bubble layers," Proc. ICS 24th conference, paper ABS-0888 (2022).
  5. K. W. Commander and A. Prosperetti, "Linear pressure waves in bubbly liquids: Comparison between theory and experiments," J. Acoust. Soc. Am. 85, 732-746 (1989). https://doi.org/10.1121/1.397599