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지그재그 구조 메타물질을 이용한 음향 소음기 설계

Design of acoustic meta-material silencer based on coiled up space

  • 심기훈 (부산대학교 기계공학부) ;
  • 장준영 (부산대학교 기계공학부) ;
  • 권호진 (부산대학교 기계공학부) ;
  • 송경준 (부산대학교 기계공학부)
  • 투고 : 2020.12.09
  • 심사 : 2020.12.28
  • 발행 : 2021.01.31

초록

본 논문은 덕트 내 소음을 저감하기 위해 저주파 대역에서 작동하는 음향메타물질 소음기를 개발하는데 목적이 있다. 지그재그 도파관 구조물과 헬름홀츠 형상을 조합하여, 음파의 공간상 진행 속도를 줄이는 고 굴절 메타물질 기반 음향 소음기를 설계하였다. 파장보다 매우 작은 도파관에서 점성 및 열 감쇠 효과를 계산하기 위해 점성 및 열 매쉬를 도입하여 Finite Element Method(FEM) 해석을 진행하였다. 4-Microphone Method를 이용하여 해석 결과로부터 반사율, 투과율과 흡음률을 구했으며, 지그재그 구조 소음기의 구조물 간격을 변화시켜 차단 주파수와 투과손실을 조절할 수 있음을 확인하였다. 또한, 메타물질들을 직렬 및 병렬 배열하여 광대역으로 소음을 차단하는 메타물질 소음기를 제시하였다.

In this paper, we design an acoustic meta-material silencer that operates at low frequency to reduce noise in duct. A high refractive index meta-material silencer is demonstrated with a combination of zigzag structured thin waveguide and helmholtz resonator, which reduces the speed of sound. Finite Element Method (FEM) analysis via thermo-viscous acoustic mesh is performed in order to calculate thermo-viscous dissipation in sub-wavelength waveguide. Sound power reflection, transmission and absorption coefficients are obtained utilizing 4-Microphone Method. The results show that cut-off frequency and transmission loss can be controlled through adjusting intervals of the zigzag structures. A wide-band acoustic silencer is also suggested by connecting meta-materials in series or parallel.

키워드

참고문헌

  1. S. A. Cummer, J. Christensen, and A. Alu, "Controlling sound with acoustic metamaterials," Nature Reviews Materials, 1.3, 1-13 (2016).
  2. N. Fang, D. Xi, J. Xu, M. Ambati, W. Srituravanich, C. Sun, and X. Zhang, "Ultrasonic metamaterials with negative modulus," Nature Materials, 5, 452-456 (2006). https://doi.org/10.1038/nmat1644
  3. Z. Liu, X. Zhang, Y. Mao, Y. Y. Zhu, Z. Yang, C. T. Chan, and P. Sheng, "Locally resonant sonic materials," Science, 289, 1734-1736 (2000). https://doi.org/10.1126/science.289.5485.1734
  4. K. Song, K. Kim, S. Hur, J. H. Kwak, J. Park, J. R. Yoon, and J. Kim, "Sound pressure level gain in an acoustic metamaterial cavity," Scientific Reports, 4, 7421 (2014). https://doi.org/10.1038/srep07421
  5. H. Chen and C. T. Chan, "Acoustic cloaking in three dimensions using acoustic metamaterials," Applied physics letters, 91, 183518 (2007). https://doi.org/10.1063/1.2803315
  6. M. Anzan-Uz-Zaman, K. Song, D. G. Lee, and S. Hur, "A novel approach to fabry-perot-resonance-based lens and demonstrating deep-subwavelength imaging," Scientific Reports, 10, 1-10 (2020). https://doi.org/10.1038/s41598-019-56847-4
  7. S. H. Lee and O. B. Wright, "Origin of negative density and modulus in acoustic metamaterials," Physical Review B, 93, 024302 (2016). https://doi.org/10.1103/physrevb.93.024302
  8. J. J. Park, K. J. B. Lee, O. B. Wright, M. K. Jung, and S. H. Lee, "Giant acoustic concentration by extraordinary transmission in zero-mass metamaterials," Physical Review Letters, 110, 244302 (2013). https://doi.org/10.1103/PhysRevLett.110.244302
  9. Z. Liang and J. Li, "Extreme acoustic metamaterial by coiling up space," Physical Review Letters, 108, 114301 (2012). https://doi.org/10.1103/PhysRevLett.108.114301
  10. X. Wang, X. Luo, B. Yang, and Z. Huang, "Ultrathin and durable open metamaterials for simultaneous ventilation and sound reduction," Applied Physics Letters, 115, 171902 (2019). https://doi.org/10.1063/1.5121366
  11. R. Ghaffarivardavagh, J. Nikolajczyk, S. Anderson, and X. Zhang, "Ultra-open acoustic metamaterial silencer based on Fano-like interference," Physical Review B, 99, 024302 (2019). https://doi.org/10.1103/PhysRevB.99.024302