Cube-Shaped Sound-Insulating Enclosures: Experimental Tests and Calculation Models

Downloads

Authors

Abstract

The research described in this article concerns sound-insulating enclosures used for sound sources imitating a noisy machine or device. It is a continuation of experimental tests and modelling studies previously conducted on a prototype test stand, in which the enclosure walls measured 0.7 m × 0.7 m. The main aim of the current research was to estimate the acoustic efficiency of the enclosures through experimental testing on a new stand with walls measuring 0.55 m × 0.55 m, conducted under conditions similar to those found in an industrial facility. Tests conducted on five wall types of varying thicknesses, made of materials such as steel, aluminium, and plexiglass, enabled the development of a calculation model for insertion loss (IL), which can be used based on the material data for the enclosure walls. The model was validated through further experimental tests covering four additional material variants, and a high correlation of the results was obtained. The influence of the calculation model used for the enclosure wall transmission loss on the IL result was also investigated. The results of the experimental tests and modelling studies were also compared with those obtained for a larger enclosure made of the same wall materials. The research described in the current article may have practical applications in the selection of walls of cube-shaped enclosures and in estimating their effectiveness in a cost-free manner, assuming that appropriate material data are used in the calculations.

Keywords:

acoustical enclosures, insertion loss (IL), noise protection

References


  1. Agahi P., Singh U.P., Hetherington J.O. (1999), Numerical prediction of the insertion loss for small rectangular enclosures, Noise Control Engineering Journal, 47(6): 201–208, https://doi.org/10.3397/1.599316

  2. Ahnert Feistel Media Group (2011), AFMG SoundFlow User’s Guide.

  3. Barron R.F. (2003), Industrial Noise Control and Acoustics, Marcel Dekker, Inc., New York.

  4. Chiu M.-C. (2012), Shape optimization of two-layer acoustical hoods using an artificial immune method, Archives of Acoustics, 37(2): 181–188, https://doi.org/10.2478/v10168-012-0024-5

  5. Davy J.L. (2009), Predicting the sound insulation of single leaf walls: Extension of Cremer’s model, The Journal of the Acoustical Society of America, 126(4): 1871–1877, https://doi.org/10.1121/1.3206582

  6. Hopkins C. (2007), Sound Insulation, Elsevier, Oxford.

  7. International Organization for Standardization (2010), Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure – Survey method using an enveloping measurement surface over a reflecting plane (ISO Standard No. 3746:2010), https://www.iso.org/standard/52056.html

  8. International Organization for Standardization (2012), Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure – Precision methods for anechoic rooms and hemi-anechoic rooms (ISO Standard No. 3745:2012), https://www.iso.org/standard/45362.html

  9. Kim H.-S., Kim J.-S., Lee S.-H., Seo Y.-H. (2014), A simple formula for insertion loss prediction of large acoustical enclosures using statistical energy analysis method, International Journal of Naval Architecture and Ocean Engineering, 6(4): 894–903, https://doi.org/10.2478/IJNAOE-2013-0220

  10. Kosała K. (2019), Calculation models for analysing the sound insulating properties of homogeneous single baffles used in vibroacoustic protection, Applied Acoustics, 146: 108–117, https://doi.org/10.1016/j.apacoust.2018.11.012

  11. Kosała K. (2022), Experimental tests and prediction of insertion loss for cubical sound insulating enclosures with single homogeneous walls, Applied Acoustics, 197: 108956, https://doi.org/10.1016/j.apacoust.2022.108956

  12. Kosała K. (2024), Sound insulation performance of cube-shaped enclosures, Vibrations in Physical Systems, 35(2): 2024212, https://doi.org/10.21008/j.0860-6897.2024.2.12

  13. Kosała K., Majkut L., Mleczko D., Olszewski R., Wszołek T. (2020a), Accuracy of prediction methods for sound insulation of homogeneous single baffles, Vibration in Physical Systems, 31(2): 2020210, https://doi.org/10.21008/j.0860-6897.2020.2.10

  14. Kosała K., Majkut L., Olszewski R. (2020b), Experimental study and prediction of insertion loss of acoustical enclosures, Vibrations in Physical Systems, 31(2): 2020209, https://doi.org/10.21008/j.0860-6897.2020.2.09

  15. Kosała K., Majkut L., Olszewski R., Flach A. (2020c), Laboratory tests of the prototype stand to determine the acoustic properties of materials used in noise protection, [in:] 21st Century Technologies – Current Problems and New Challenges [in Polish: Technologie XXI Wieku – Aktualne Problemy i Nowe Wyzwania], Vol. 1, pp. 7–20, Wydawnictwo Naukowe TYGIEL, Lublin.

  16. Lei Y., Pan J., Sheng M.P. (2012), Investigation of structural response and noise reduction of an acoustical enclosure using SEA method, Applied Acoustics, 73(4): 348–355, https://doi.org/10.1016/j.apacoust.2011.10.008

  17. Marshall Day Acoustics (2017), Sound Insulation Prediction Program, INSUL, User’s Manual.

  18. Ming R., Pan J. (2004), Insertion loss of an acoustic enclosure, The Journal of the Acoustical Society of America, 116(6): 3453–34599, https://doi.org/10.1121/1.1819377

  19. Nieradka P., Dobrucki A. (2018), Insertion loss of enclosures with lined slits, [in:] Proceedings of the 11th European Congress and Exposition on Noise Control Engineering Euronoise Conference, pp. 893–898.

  20. Oldham D.J., Hillarby S.N. (1991), The acoustical performance of small close fitting enclosure, part 1: Theoretical models, The Journal of Sound and Vibrations, 150(2): 261–281, https://doi.org/10.1016/0022-460X(91)90620-Y

  21. Pawelczyk M., Wrona S. (2022), Noise-Controlling Casings, CRC Press, Boca Raton.

  22. Sharp B.H. (1973), A study of techniques to increase the sound insulation of building elements, Technical Report, US Department of Commerce, National Technical Information Service, Washington.

  23. Ver I.L., Beranek L.L. (2006), Noise and Vibration Control Engineering – Principles and Applications, 2nd ed., John Wiley & Sons, Inc., Hoboken, New Jersey.

  24. Zhou L., Carter A.E., Herrin D.W., Shi J., Copley D.C. (2011), Airborne path attenuation of partial enclosures: Simulation and sensitivity study, Applied Acoustics, 72(6): 380–386, https://doi.org/10.1016/j.apacoust.2010.12.012