Development and optimization of noise barrier

Absorber structure

• measurement of the spectral sound absorption coefficient for perpendicular sound incidence at cylindrical specimens of open porous structures by means of the impedance tube AcoustiTube^® according to DIN EN ISO 10534-2 and ASTM E1050

• measurement of the spectral sound absorption coefficient for angular and statistical sound incidence at plates of open porous structures in the free sound field above reflecting ground by means of the sound absorption measuring device AcoustiAdrienne according to DIN EN ISO 13472-1 and DIN EN 1793-5

• measurement of the spectral sound absorption coefficient for diffuse sound incidence at plates of open porous structures in the reverberation chamber according to DIN EN ISO 354 or in the Alpha cabine in the sense of DIN EN ISO 354.

• measurement of the airflow resistance at cylindrical specimens and plates of open porous structures by means of the airflow resistivity meter AcoustiFlow^® on the basis of the static-airflow method described in DIN EN ISO 9053-1 (former DIN EN 29053)

• measurement of additional material parameters of open porous structures to predict / to optimize the sound absorbing capability, e. g.
  • complex wave number, complex impedance (absorber values)
  • gross density, porosity (accessible void content)
  • tortuosity, structure factor
• computational prediction of the spectral sound absorption coefficient for perpendicular / angular / diffuse sound incidence at open porous structures by application of various absorber models under consideration of multi-layer systems with associated material parameters

• acoustical design of 3D structure surfaces (e. g. pyramid structure or wave structure) to optimize the spectral sound absorption coefficient by means of numerical simulation on the basis of the finite element method (FEM)

Massive wall

• measurement of the spectral airborne sound insulation in test setups for windows, doors and walls according to DIN EN ISO 10140-2; rating according to DIN EN ISO 717-1

• computational prediction of the spectral sound insulation at massive building elements by application of various elastic models under consideration of multi-layer systems with associated material parameters

Crown element

• acoustic design and optimization of passive crown elements of noise screens to increase the spectral insertion loss of noise barriers by means of numerical simulation on the basis of the finite element method (FEM) and by taking advantage of various effects (e. g. absorption, resonance, diffraction)

Entire noise barrier

• computational prediction of the spectral sound insulation at massive building elements with open porous structures at the front side and the rear side of the screen by application of various elastic models in combination with various absorber models under consideration of multi-layer systems with associated material parameters

• computational prediction of the immission sound pressure level and the spectral insertion loss of the noise barrier at the site of sound immission by means of analytical and numerical calculation under consideration of source-receiver-geometry as well as noise barrier with absorber structure and crown element

• examination of acoustic efficiency of absorbing facings and crowns of noise screens by scale-model measurements in the anechoic chamber

• acoustic design of a noise barrier in the vicinity traffic routes according to VDI 2720, part 1

Acoustic testing and evaluation of noise barrier

Absorber structure

• measurement of the spectral sound absorption coefficient for diffuse sound incidence at a noise barrier according to in the reverberation chamber according to DIN EN 1793-1

• non-destructive (in situ) measurement of the spectral sound absorption coefficient for angular and statistical sound incidence at a noise barrier with sound absorption measuring device AcoustiAdrienne according to DIN CEN/TS 1793-5, DIN EN 1793-5 and DIN CEN/TS 16272-5, evaluation according to ZTV Lsw 06 and ZTV Lsw 21

Massive wall

• measurement of the spectral airborne sound insulation of a noise barrier in the test setup for walls according to DIN EN 1793-2

• non-destructive (in situ) measurement of the spectral airborne sound insulation of a noise barrier with measuring system AcoustiAdrienne according to DIN EN 1793-6 and DIN EN 16272-6

Crown element

• non-destructive (in situ) measurement of the spectral Miller index of a noise barrier and the Miller index difference of a crown element of noise screens (influence of crown element on the sound diffraction) with measuring system AcoustiAdrienne according to DIN EN 1793-4 and DIN EN 16272-4

Entire noise barrier

• measurement of the immission sound pressure level and the spectral insertion loss of the noise barrier at the site of sound immission by means of novel measurement procedure with microphone array
  • taking advantage of the directivity of the microphone array
  • saving of building costs by strong reduction of required length of the noise screen to be investigated in comparison to commonly applied standard measurement procedure with single microphone