International Journal of Automotive Technology

The Korean Society of Automotive Engineers (한국자동차공학회)
권호 표지

NOISE REDUCTION OF AN ENCLOSED CAVITY BY MEANS OF AIR-GAP SYSTEMS

  • Kang, S.W. (Department of Mechanical Systems Engineering, Hansung University) ;
  • Lee, J.M. (School of Mechanical and Aerospace Engineering, Seoul National University)
  • Published : 2004.09.01
Download PDF
⟨ Previous Next ⟩

Abstract

The objective of this paper is to introduce the noise reduction characteristics of a double gap system, which is composed of two air-gaps and two partition sheets. The resonance of acoustic modes of an enclosed cavity can be effectively suppressed by installing the double gap system in the cavity. It is revealed from a simple, one-dimensional model that the double gap system is more effective than the single gap system that consists of one air-gap and one partition sheet, in that the former requires a smaller space than the latter. Finally, these theoretical conclusions are verified by comparison experiments using an actually manufactured enclosed cavity, of which the boundary surfaces are made of thick panels that can be assumed as rigid walls.

Keywords

References

  1. Chanaud, R. C. (1994). Effects of geometry on the resonance frequency of Helmholtz resonators. Journal of Sound and Vibration 178, 337-348 https://doi.org/10.1006/jsvi.1994.1490
  2. Chanaud, R. C. (1997). Effects of geometry on the resonance frequency of Helmholtz resonators, Part II. Journal of Sound and Vibration 204, 829-834 https://doi.org/10.1006/jsvi.1997.0969
  3. Dickey, N. S. and Se1amet, A. (1996). Helmholtz resonators: One-dimensional limit for small cavity length-todiameter ratios. Journal of Sound and Vibration 195, 512-517 https://doi.org/10.1006/jsvi.1996.0440
  4. Kang, S. W., Lee, J. M. and Kim, S. H. (2000). Structural- acoustic coupling analysis on vehicle passenger compartment with the roof, air-gap, and trim boundary. Journal of Vibration and Acoustics 112, 196-202
  5. Kang, S. W. and Lee, J. M. (2003). Sound absorption characteristics of air-gap systems in enclosed cavities. Journal of Sound and Vibration 259, 209-218 https://doi.org/10.1006/jsvi.2002.5074
  6. Ko, K. H., Heo, J. J. and Kook, H. (2003). Evaluation of road-induced noise of a vehicle using experimental approach. Int. J. Automotive Technology 4, 1, 21-30
  7. Reynolds, D. (1981). Engineering Principles of Acoustics Noise and Vibration Control. Allyn and Bacon 333-344
  8. Selamet, A., Radavich, P. M., Dickey, N. S. and Novak, J. M. (1997). Circular concentric Helmholtz resonators. Journal of the Acoustical Society of America 101, 41-51 https://doi.org/10.1121/1.417986
  9. Selamet, A. and Ji, J. L. (1997). Circular asymmetric Helmholtz resonators. Journal of the Acoustical Society of America 107, 2360-2369