Results from a numerical study examining micro-macro relations linking local geometry parameters to sound absorption properties are presented. For an hexagonal structure of solid fibers, the porosity , the thermal characteristic length ’, the static viscous permeability k0, the tortuosity , the viscous characteristic length , and the sound absorption coefficient are computed. Numerical solution...

Results from a numerical study examining micro-/macrorelations linking local geometry parameters to sound absorption properties are presented. For a hexagonal structure of solid fibers, the porosity phi, the thermal characteristic length Lambda('), the static viscous permeability k(0), the tortuosity alpha(infinity), the viscous characteristic length Lambda, and the sound absorption coefficient...

This work experimentally studied locally resonant absorption mechanism in phononic glass. From these results, we attributed its strong sound attenuation to its locally resonant units and its broadband absorption to its networked structure. These experiments also indicated that the porosity of the phononic glass must be tuned to achieve the best sound absorption at given frequencies.

Based on the quantum transport equation for the electron-phonon system, the absorption coefficient of sound (acoustic phonons) by absorption of laser radiation in cylindrical quantum wires is calculated for the case of monophoton absorption and the case of multiphoton absorption. Analytical expressions and conditions for the absorption of sound are obtained. Differences between the two cases of...

This paper puts forward a scheme to form perlite sound absorption boards by vibration molding according to the material properties and the characteristics of vibration forming method. In the trial, the feasibility and reliability of this method were confirmed by studying the effect of working pressure, frequency and vibration force on the quality of the perlite sound absorption board. Besides, ...