Transactions of the Korean Society for Noise and Vibration Engineering (한국소음진동공학회논문집)

The Korean Society for Noise and Vibration Engineering (한국소음진동공학회)
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Noise Reduction Effect of an Air Bubble Layer on an Infinite Flat Plate

무한 평판 주위에 형성된 수중 기포층의 방사소음 감소 효과

  • 김종철 (국방과학연구소 제2체계개발본부) ;
  • 오준석 (국방과학연구소 제2체계개발본부) ;
  • 조대승 (부산대학교 조선해양공학과)
  • Published : 2007.02.20
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Abstract

The mixture sound speed in bubbly fluids is highly dispersive due to differences of the density and compressibility between bubbles and fluids. The dispersion range in bubbly fluids expands to a higher frequency than the resonance frequency of an air bubble. A theoretical model was developed to compute the reduction of radiation noise that is generated by a force applied on an infinite flat plate using a bubble layer as a compliant baffle. For evaluating the effectiveness of a bubble layer in reducing the structure-borne noise of an infinite elastic plate, the noise reduction levels for various parameters such as the thickness of bubble layers, the volume fractions and the distribution types of bubbly fluids are calculated numerically. The noise reduction effect of an air bubble layer on an infinite flat plate is considerable level and similar to the tendency of dispersion of bubbly fluids. It is recommended that the thickness of a bubble layer should be increased with keeping an appropriate volume fraction of an air bubble for the most effective reduction of the radiation noise.

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References

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