The Journal of the Acoustical Society of Korea (한국음향학회지)

The Acoustical Society of Korea (한국음향학회)
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A study on the acoustic performance of a silencer according to the change of properties of absorbing material

흡음재 물성치 변화에 따른 소음기 음향성능 연구

  • Received : 2021.05.03
  • Accepted : 2021.06.29
  • Published : 2021.07.31
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Abstract

In this study, the acoustic performance of a dissipative silencer used in the ship with excellent performance compared to its size was predicted and analyzed using a numerical analysis method to reduce the pipe noise. To this end, the performance of the single expansion chamber-shaped silencer was verified using experimental and numerical analysis methods. The acoustic performance of the silencer was expressed using the Transmission Loss (TL), an indicator of its own performance, and the result was derived using the two-load method, which measured by changing the impedance at the end of the pipe. For the numerical analysis method, a general-purpose finite element analysis program was used, and the Delany-Bazley-Miki model with the flow resistivity of the sound absorbing material as an input parameter was applied. Finally, we compared the experimental and simulated results for each of the acoustic performances of the single expansion type and the dissipative silencer to confirm the consistency of the results, and predicted and analyzed the simulation results for four cases according to the properties of the sound absorbing material.

본 연구에서는 함정에서 발생하는 배관소음을 줄이기 위해 크기 대비 성능이 우수한 흡음형 소음기의 음향성능을 수치해석 방법을 이용하여 예측 및 분석하였다. 이를 위해 단일확장형 소음기의 음향성능을 실험 및 수치해석 방법을 이용하여 검증하였다. 음향성능은 자체 성능을 나타내는 지표인 투과손실을 이용하여 나타내었고, 실험은 배관 끝단 임피던스를 바꿔서 측정하는 two-load method를 통해 결과를 도출하였다. 수치해석은 범용 유한요소해석 프로그램을 사용하여 실시하였고, 흡음재 유동저항을 입력 매개변수로 하는 Delany-Bazley-Miki 모델을 적용하였다. 최종적으로, 단순확장형 및 흡음형 소음기 음향성능 각각에 대한 실험·모의 결과를 비교하여 결과의 일치성을 확인하였으며, 흡음재 물성치에 따라 4가지 경우로 분류하여 각각에 대한 시뮬레이션 결과를 예측 및 분석하였다.

Keywords

Acknowledgement

본 논문은 2021년 해군사관학교 해양연구소의 지원을 받아 수행된 연구임을 밝히며, 지원에 감사드립니다.

References

  1. M. B. Xu, A. Selamet, I. J. Lee, and N. T. Huff, "Sound attenuation in dissipative expansion chambers," J. Sound Vib. 272, 1125-1133 (2004). https://doi.org/10.1016/j.jsv.2003.07.025
  2. D. Potente, "General design principles for an automotive muffler," Proc. ACOUSTICS, 153-158 (2005).
  3. A. Craggs, "A finite element method for modelling dissipative mufflers with a locally reactive lining," J. Sound Vib. 54, 285-296 (1977). https://doi.org/10.1016/0022-460X(77)90030-X
  4. M. L. Munjal, Acoustics of Ducts and Mufflers (Wiley, New York, 2014), pp. 85-87.
  5. K. S. Peat, "A transfer matrix for an absorption silencer element," J. Sound Vib. 146, 353-360 (1991). https://doi.org/10.1016/0022-460X(91)90770-K
  6. Z. Tao and A. F. Seybert, "A review of current techniques for measuring muffler transmission loss," SAE transactions, 2096-2100 (2003).
  7. A. Selamet, M. B. Xu, I. J. Lee, and N. T. Huff, "Dissipative expansion chambers with two concentric layers of fibrous materail," Int. J. Veh. Noise Vib. 1, 341-357 (2005). https://doi.org/10.1504/IJVNV.2005.007531
  8. A. Selamet, M. B. Xu, I. J. Lee, and N. T. Huff, "Analytical approach for sound attenuation in perforated dissipative silencers," J. Acoust. Soc. Am. 115, 2091-2099 (2004). https://doi.org/10.1121/1.1694994
  9. D. Veerababu and B. Venkatesham, "Green's function approach for the transmission loss of concentrically multi-layered circular dissipative chamber," J. Acoust. Soc. Am. 147, 867-876 (2020). https://doi.org/10.1121/10.0000675
  10. A. Dincer and M. Caliskan, "Experimental analysis of dissipative silencer coupled with quarter wave tube," Forum Acusticum, 1-6 (2014).
  11. A. Selamet and P. M. Radavich, "The effect of length on the acoustic attenuation performance of concentrick expansion chambers: an analytical, computational and experimental investigation," J. Sound Vib. 201, 407-426 (1997). https://doi.org/10.1006/jsvi.1996.0720
  12. M. E. Delany and E. N. Bazley, "Acoustical properties of fibrous absorbent materials," Applied acoustics. 3, 105-116 (1970). https://doi.org/10.1016/0003-682X(70)90031-9
  13. C. Zwikker and C. W. Kosten, Sound Absorbing Materials (Elsevier, Oxford, 1949), pp. 25-44.
  14. K. Attenborough, "On the acoustic slow wave in air-filled granular media," J. Acoust. Soc. Am. 81, 93-102 (1987). https://doi.org/10.1121/1.394938
  15. Y. Miki, "Acoustical properties of porous materialsModifications of Delany-Bazley models," J. Acoust. Soc. Jpn. 11, 19-24 (1990). https://doi.org/10.1250/ast.11.19
  16. I. Lee, Acoustic characteristics of perforated dissipative and hybrid silencers, (Ph.D. Dissertation, Ohio State University, 2005).
  17. T. J. Cox and P. D'antonio, Aabsorbers and Diffusers: Theory, Design and Application (Crc Press, London, 2009), pp. 138-140.
  18. A. I. El Sharkawy and A. H. Nayfeh, "Effect of an expansion chamber on the propagation of sound in circular ducts," J. Acoust. Soc. Am. 63, 667-674 (1978). https://doi.org/10.1121/1.381792
  19. Jochenschulz, https://www.jochenschulz.me/en/blog/rockwool-glasswool-hemp-best-absorber-material/, (Last viewed May 22, 2021).