Acoustic Analysis with Consideration of Damping Effects of Air Viscosity in Sound Pathway
Sound pathways in the enclosures of small earphones
are very narrow. In such narrow pathways, the speed of sound
propagation and the phase of sound waves change because of the air
viscosity. We have developed a new finite element method that
includes the effects of damping due to air viscosity for modeling the
sound pathway. This method is developed as an extension of the
existing finite element method for porous sound-absorbing materials.
The numerical calculation results using the proposed finite element
method are validated against the existing calculation methods.
[1] T. Yamaguchi, J. Tsugawa, H. Enomoto and Y. Kurosawa, "Layout of
Sound Absorbing Materials in 3D Rooms Using Damping Contributions
with Eigenvectors as Weight Coefficients", Journal of System Design and
Dynamics, Vol. 4-1, pp. 166-176, 2010.
[2] T. Yamaguchi, Y. Kurosawa and H. Enomoto, "Damped Vibration
Analysis Using Finite Element Method with Approximated Modal
Damping for Automotive Double Walls with a Porous Material", Journal
of Sound and Vibration, Vol. 325, pp. 436-450, 2009.
[3] M. Sasajima, T. Yamaguchi and A. Hara, "Acoustic Analysis Using
Finite Element Method Considering Effects of Damping Caused by Air
Viscosity in Audio Equipment", Applied Mechanics and Materials, Vol.
36, pp. 282-286, 2010.
[4] H. Utsuno, T. Tanaka, Y. Morisawa and T. Yoshimura, "Prediction of
Normal Sound Absorption Coefficient for Multi-Layer Sound Absorbing
Materials by Using the Boundary Element Method", Transactions of
Japan Society of Mechanical Engineers, Vol. 56-532C, pp. 3248-3252,
1990.
[5] A. Craggs and J.G.Hildebrandt, "Effective densities and resistivities for
acoustic propagation in narrow tubes", Journal of Sound and Vibration,
Vol.92, pp321-331, 1984.
[6] M. A. Biot, "Theory of Propagation of Elastic Waves in a Fluid-Saturated
Porous Solid. Ôàí. Higher Frequency Range", Journal of the Acoustical
Society of America, Vol.28, pp179-191, 1956.
[1] T. Yamaguchi, J. Tsugawa, H. Enomoto and Y. Kurosawa, "Layout of
Sound Absorbing Materials in 3D Rooms Using Damping Contributions
with Eigenvectors as Weight Coefficients", Journal of System Design and
Dynamics, Vol. 4-1, pp. 166-176, 2010.
[2] T. Yamaguchi, Y. Kurosawa and H. Enomoto, "Damped Vibration
Analysis Using Finite Element Method with Approximated Modal
Damping for Automotive Double Walls with a Porous Material", Journal
of Sound and Vibration, Vol. 325, pp. 436-450, 2009.
[3] M. Sasajima, T. Yamaguchi and A. Hara, "Acoustic Analysis Using
Finite Element Method Considering Effects of Damping Caused by Air
Viscosity in Audio Equipment", Applied Mechanics and Materials, Vol.
36, pp. 282-286, 2010.
[4] H. Utsuno, T. Tanaka, Y. Morisawa and T. Yoshimura, "Prediction of
Normal Sound Absorption Coefficient for Multi-Layer Sound Absorbing
Materials by Using the Boundary Element Method", Transactions of
Japan Society of Mechanical Engineers, Vol. 56-532C, pp. 3248-3252,
1990.
[5] A. Craggs and J.G.Hildebrandt, "Effective densities and resistivities for
acoustic propagation in narrow tubes", Journal of Sound and Vibration,
Vol.92, pp321-331, 1984.
[6] M. A. Biot, "Theory of Propagation of Elastic Waves in a Fluid-Saturated
Porous Solid. Ôàí. Higher Frequency Range", Journal of the Acoustical
Society of America, Vol.28, pp179-191, 1956.
@article{"International Journal of Mechanical, Industrial and Aerospace Sciences:57686", author = "M. Sasajima and M. Watanabe and T. Yamaguchi and Y. Kurosawa and Y. Koike", title = "Acoustic Analysis with Consideration of Damping Effects of Air Viscosity in Sound Pathway", abstract = "Sound pathways in the enclosures of small earphones
are very narrow. In such narrow pathways, the speed of sound
propagation and the phase of sound waves change because of the air
viscosity. We have developed a new finite element method that
includes the effects of damping due to air viscosity for modeling the
sound pathway. This method is developed as an extension of the
existing finite element method for porous sound-absorbing materials.
The numerical calculation results using the proposed finite element
method are validated against the existing calculation methods.", keywords = "Simulation, FEM, air viscosity, damping.", volume = "7", number = "6", pages = "1166-6", }