Acoustical efficiency of a sonic crystal assisted noise barrier

This research work aims at evaluating the acoustic performance of a noise reducing device which combines sonic crystals with a conventional noise barrier. Numerical simulations, using a 2D Boundary Element Method (BEM), are carried out to evaluate their acoustic properties in terms of insertion and reflection losses due to the addition of the sonic crystal elements. The studied so-called sonic crystal assisted noise barrier is 3m high and 1m wide and is composed of two periodic bands of scatterers combined with a rigid straight barrier. Resonant cavities are used to produce extra insertion loss at some frequencies of resonance below the band gaps. Improved attenuation properties are found when resonant scatterers (cavities) and absorbent materials are combined. Our results show a significant extra insertion loss due to the addition of the sonic crystal elements for middle and high frequencies of typical road traffic noise. On the other hand, the extra reflection loss is limited.

[1]  Sean F. Wu,et al.  The Boundary Element Method in Acoustics , 2000 .

[2]  K. Attenborough,et al.  Predictions and measurements of sound transmission through a periodic array of elastic shells in air. , 2010, The Journal of the Acoustical Society of America.

[3]  J. V. Sánchez-Pérez,et al.  Acoustic insertion loss due to two dimensional periodic arrays of circular cylinders parallel to a nearby surface. , 2011, Journal of the Acoustical Society of America.

[4]  R. Martínez-Sala,et al.  SOUND ATTENUATION BY A TWO-DIMENSIONAL ARRAY OF RIGID CYLINDERS , 1998 .

[5]  P A Deymier,et al.  Phononic crystal with low filling fraction and absolute acoustic band gap in the audible frequency range: a theoretical and experimental study. , 2002, Physical review. E, Statistical, nonlinear, and soft matter physics.

[6]  P. Jean,et al.  THE IMPORTANCE OF SOURCE TYPE ON THE ASSESSMENT OF NOISE BARRIERS , 1999 .

[7]  D. Duhamel.  EFFICIENT CALCULATION OF THE THREE-DIMENSIONAL SOUND PRESSURE FIELD AROUND A NOISE BARRIER , 1996 .

[8]  C. Linton,et al.  Effects of porous covering on sound attenuation by periodic arrays of cylinders. , 2006, The Journal of the Acoustical Society of America.

[9]  E. N. Bazley,et al.  Acoustical properties of fibrous absorbent materials , 1970 .

[10]  B. Djafari-Rouhani,et al.  Acoustic band structure of periodic elastic composites. , 1993, Physical review letters.

[11]  V. Twersky,et al.  Multiple Scattering of Radiation by an Arbitrary Configuration of Parallel Cylinders , 1952 .

[12]  J. V. Sánchez-Pérez,et al.  Acoustic barriers based on periodic arrays of scatterers , 2002 .

[13]  Vicent Romero-García,et al.  Acoustic Barriers Based on Sonic Crystals , 2007 .

[14]  Dick Botteldooren,et al.  Effect of a Row of Trees Behind Noise Barriers in Wind , 2002 .

[15]  Sheng,et al.  Locally resonant sonic materials , 2000, Science.

[16]  Sébastien Guenneau,et al.  Split-ring resonators and localized modes , 2004 .

[17]  P. Jean.  A VARIATIONAL APPROACH FOR THE STUDY OF OUTDOOR SOUND PROPAGATION AND APPLICATION TO RAILWAY NOISE , 1998 .

[18]  Hans Jonasson,et al.  Source modelling of road vehicles , 2004 .