3D Multi-Domain MFS Analysis of Sound Pressure Level Reduction Between Connected Enclosures

• Autorzy: Godinho L. , Branco F. G. , Mendes P. A. P. A.
• Języki publikacji: EN

Abstrakty

EN

In this paper, the authors study the 3D propagation of sound waves between two closed spaces. The separation element between the two rooms is considered to include either a small opening or a homogeneous lightweight panel, coupling the two spaces. A numerical study of this configuration is performed, trying to understand the influence of the position and geometry of this opening in the sound pressure level reduction curve at low and midfrequencies. Additionally, the coupling effect between the two acoustic spaces is analyzed, in order to better understand its importance when determining the sound pressure level reduction. Different boundary conditions are ascribed to the walls of these rooms, simulating both the completely reflecting and partially absorbing surfaces. The numerical modelling was performed using a multi-domain formulation of the Method of Fundamental Solutions (MFS). The system is composed of two coupled rooms, limited by rigid or by absorbing walls, and separated by a thin wall (tending to null thickness) with a small opening. An experimental validation of the proposed model is presented, comparing its results with those found experimentally for a reduced-scale model. It is important to note that, for such a configuration, a traditional single-domain approach using methods like the MFS or the BEM would lead to undetermined equation systems, and thus the proposed model makes use of a domain decomposition technique.

Słowa kluczowe

EN

Method of Fundamental Solutions (MFS); domain decomposition; closed spaces; sound pressure level reduction

• Wydawca: Instytut Podstawowych Problemów Techniki PAN ; Komitet Akustyki PAN ; Polskie Towarzystwo Akustyczne
• Czasopismo: Archives of Acoustics
• Rocznik: 2011
• Tom: Vol. 36, No. 3
• Strony: 575--601
• Opis fizyczny: Bibliogr. 26 poz., wykr.

Twórcy

autor

Godinho L.

autor

Branco F. G.

autor

Mendes P. A. P. A.

• University of Coimbra CICC, Department of Civil Engineering Pólo 2 – FCTUC Rua Luýs Reis Santos, 3030-788 Coimbra, Portugal,

Bibliografia

• 1. Alves C., Valtchev S. (2005), Numerical comparison of two meshfree methods for acoustic wave scattering, Engineering Analysis with Boundary Elements, 29, 371-82.
• 2. Antóio J., Tadeu A., Godinho L. (2008), A three-dimensional acoustics model using the method of fundamental solutions, Engineering Analysis with Boundary Elements, 32, 525-531.
• 3. Atluri S.N. (2004), The Meshless Method (MLPG) for Domain and BIE Discretizations, Tech. Science Press, USA.
• 4. Beranek L. L., V큖r I.L. (1992), Noise and Vibration Control Engineering, Principles and Applications, Wiley, New York, USA.
• 5. Bradley D., Wang L. (2009), Quantifying the Double Slope Effect in Coupled Volume Room Systems, Journal of Building Acoustics, 16, 2.
• 6. Craik R. (1996), Sound Transmission Through Buildings Using Statistical Energy Analysis, Gower Publishing Limited, Hampshire, England.
• 7. Fairweather G., Karageorghis A. (1998), The method of fundamental solutions for elliptic boundary value problems, Adv. Comput. Math., 9, 69-95.
• 8. Fairweather G., Karageorghis A., Martin P.A. (2003), The method of fundamental solutions for scattering and radiation problems, Engineering Analysis with Boundary Elements, 27, 759-69.
• 9. Godinho L., Tadeu A. (2002), The Importance of a Small Wall Deformation in the Three-Dimensional Acoustic Logging Results, Geophysical Journal International, 151, 2, 403-415.
• 10. Godinho L., Tadeu A., Amado-Mendes P. (2007), Wave propagation around thin structures using the MFS, Computers Materials & Continua (CMC), 5, 2, 117-127.
• 11. Godinho L., Tadeu A., Sim˜oes N. (2006), Accuracy of the MFS and BEM on the analysis of acoustic wave propagation and heat conduction problems, [in:] Advances in the Meshless Method: 2005, J. Sladek, V. Sladek and S.N. Atluri [Eds.], Techscience Press, USA.
• 12. Golberg M., Chen C.S. (1999), The method of fundamental solutions for potential, Helmholtz and diffusion problems. Boundary Integral Methods: Numerical and Mathematical Aspects, Computational Engineering, Vol. 1. Boston, MA: WIT Press/Computational Mechanics Publications, p. 103-176.
• 13. Kansa E. (1990a), Multiquadrics - A scattered data approximation scheme with applications to computational fluid-dynamics - I: Surface approximations and partial derivative estimates, Comput. Math. Appl., 19, 127-145.
• 14. Kansa E. (1990b), Multiquadrics - A scattered data approximation scheme with applications to computational fluid-dynamics - II: Solutions to parabolic, hyperbolic and elliptic partial differential equations, Comput. Math. Appl., 19, 147-161.
• 15. Maluski S., Gibbs B. (2000), Application of a finite-element model to low-frequency sound insulation in dwellings, Journal of the Acoustical Society of America, 108, 4, 1741-1751.
• 16. Marburg S., Nolte B. (2008), Computational Acoustics of Noise Propagation in Fluids: Finite and Boundary Element Methods, Springer-Verlag, Berlin, Germany.
• 17. Mechel F. (2002), Formulas of Acoustics, SpringerVerlag, Berlin, Germany.
• 18. Meissner M. (2009), Computer modelling of coupled spaces: variations of eigenmodes frequency due to a change in coupling, Archives of Acoustics, 34, 2, 157-168.
• 19. Santos P., Tadeu A. (2002), Acoustic insulation provided by a single wall separating two contiguous tunnels via BEM, Journal of Sound and Vibration, 257, 5, 945-965.
• 20. Sharp B.H. (1978), Prediction methods for the sound transmission of building elements, Noise Control Engineering Journal, 11, 53-63.
• 21. Steel J., Craik R. (1994), Statistical energy analysis of structure-borne sound transmission by Finite Element Methods, Journal of Sound and Vibration, 178, 553-561.
• 22. Tadeu A., Ant?io J. (2002), Acoustic insulation of single panel walls provided by analytical expressions versus the mass law, Journal of Sound and Vibration, 257, 3, 457-475.
• 23. Tadeu A., Ant?io J., Godinho L. (2000), Frequency and Time Numerical Solutions of 3D Sound Propagation in Open and Closed Spaces, Journal of Building Acoustics, 7, 4, 247-261.
• 24. Tadeu A., Godinho L. (2003), Scattering of acoustic waves by movable lightweight elastic screens, Engineering Analysis with Boundary Elements, 27, 3, 215-226.
• 25. Telles J. (1987), A self-adaptive co-ordinate transformation for efficient numerical evaluation of general boundary element integrals, International Journal for Numerical Methods in Engineering, 24, 5, 959-973.
• 26. Wu T. [Ed.] (2000), Boundary element acoustics, WIT Press, Southampton, UK