Fiber movements and sound attenuation in glass wool

Tarnow, Viggo

doi:10.1121/1.424581

Cited by 15 publications

(6 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…8 The measured elastic moduli are presented in Table I. The glass wool is much softer in the X-direction than in the other directions.…”

Section: Measurement Methods and Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Measurements of anisotropic sound propagation in glass wool

Tarnow

2000

The Journal of the Acoustical Society of America

Self Cite

View full text Add to dashboard Cite

The attenuation coefficient and phase velocity of plane sound waves propagating in three perpendicular directions in glass wool were measured in the frequency range 50-10 000 Hz. For glass wool of mass density 14 kg/m 3 at the frequency 1000 Hz, the attenuation constant for propagation perpendicular to the glass wool sheets was 75 dB/m, and for propagation parallel with the sheets 57 dB/m. For mass density 30 kg/m 3 , the corresponding numbers were 140 and 100 dB/m. The measured values were compared with calculated ones taking into account the movements of the fiber skeleton. The calculations need the elastic moduli, which were measured. For density 14 kg/m 3 and deformation perpendicular to the glass wool sheets, the static modulus was 2.0 kPa, and for parallel deformation 120 kPa. The corresponding numbers for mass density 30 kg/m 3 were 16 and 390 kPa.

show abstract

“…8 The measured elastic moduli are presented in Table I. The glass wool is much softer in the X-direction than in the other directions.…”

Section: Measurement Methods and Resultsmentioning

confidence: 99%

“…1 Fiber movement is significant, and was accounted for using a method developed previously. 8 The fiber skeleton can carry a stress wave that is coupled to the acoustic pressure wave. The air moves, and the viscous drag on the fibers makes them move.…”

Section: Calculation Of Attenuation Coefficient and Phase Velocitymentioning

confidence: 99%

Measurements of anisotropic sound propagation in glass wool

Tarnow

2000

The Journal of the Acoustical Society of America

Self Cite

View full text Add to dashboard Cite

show abstract

“…Inorganic fibers have great superiority over natural fibers in resisting fire and corrosion and have great competitive edge in prices, but are limited in practical use due to their threat to the environment and human well-being. In the field of inorganic fibers, glass fibers (Kino & Ueno, 2008a;Tarnow, 1999Tarnow, , 2000Tarnow, , 2002Wang & Tong, 2001) are the most typical inorganic sound absorption materials. The occurrence of synthetic fibers expands the field of research as they are exceptional in sound absorption, corrosion-resistance, and are recyclable, of which polypropylene fibers (Alonso et al, 1992;Chen & Jiang, 2007) and polyester fibers (Garai & Pompoli, 2005;Kino & Ueno, 2008b;Tascan & Vaughn, 2008) are the most typical.…”

Section: Introductionmentioning

confidence: 99%

Effects of different parameters on acoustic properties of activated carbon fiber felts

Shen

Jiang

2013

The Journal of The Textile Institute

View full text Add to dashboard Cite

The aim of this study is to explore the effects of different parameters on acoustic properties of activated carbon fiber felts. Seven viscose-based activated carbon fiber felts with different specifications were selected to test the sound absorption coefficients in normal incidence by using transfer-function method and an impedance tube in an acoustic range of 250-6300 Hz frequencies, and to analyze the effects on acoustic properties caused by factors such as: thickness, bulk density, and fiber diameter. The result demonstrated that activated carbon fiber felts exhibited exceptional acoustic properties. As frequency increases, sound absorption coefficients of less-thick felts went upwards in the whole range of frequencies; when the thickness amounted to 9 mm, sound absorption coefficients showed a sharp increase at low frequencies and a fluctuation at high frequencies. With the increase in thickness and bulk density, sound absorption properties improved first and then impaired at the same level of frequency; with a decrease in the fiber diameter, properties enhanced at the same level of frequency. When thickness and bulk density increased and fiber diameter decreased, sound absorption coefficients of the first resonance frequency displayed an upward trend to different degrees, while the first resonance frequencies declined discrepantly.

show abstract

“…The glass wool is dragged by the friction between fibers and moving air in the sound waves. 7,13 Calculation of the wave number by Eq. ͑11͒ assumes the fibers do not move.…”

Section: Kϭͱirc ͑11͒mentioning

confidence: 99%

Measured anisotropic air flow resistivity and sound attenuation of glass wool

Tarnow

2002

The Journal of the Acoustical Society of America

Self Cite

View full text Add to dashboard Cite

The air flow resistivity of glass wool has been measured in different directions. The glass wool was delivered from the manufacturer as slabs measuring 100ϫ600ϫ900 mm 3 , where the surface 600ϫ900 mm 2 was parallel with the conveyor belt used in the manufacturing. Directions in the glass wool are described by a coordinate system with the X axis perpendicular to the conveyor belt, the Z axis in the direction the conveyor belt moves, and the Y axis perpendicular to the two other axes. It was found that the resistivities in the Y and Z directions were equal in all cases. For density 14 kg/m 3 the mean resistivity in the X direction was 5.88 kPa s m Ϫ2 and in the Y direction 2.94 kPa s m Ϫ2. For density 30 kg/m 3 the mean resistivity in the X direction was 15.5 kPa s m Ϫ2 and in the Y direction 7.75 kPa s m Ϫ2. A formula for prediction of resistivity for other densities is given. By comparing measured values of sound attenuation with results calculated from resistivity data, it is demonstrated that the measured attenuation can be predicted in a simple manner.

show abstract

Fiber movements and sound attenuation in glass wool

Cited by 15 publications

References 10 publications

Measurements of anisotropic sound propagation in glass wool

Measurements of anisotropic sound propagation in glass wool

Effects of different parameters on acoustic properties of activated carbon fiber felts

Measured anisotropic air flow resistivity and sound attenuation of glass wool

Contact Info

Product

Resources

About