Urban Background Noise Mapping: The General Model
Journal article, 2014

Surveys show that inhabitants of dwellings exposed to high noise levels benefit from having access to a quiet side. However, current practice in noise prediction often underestimates the noise levels at a shielded facade. Multiple reflections between facades in street canyons and inner yards are commonly neglected and facades are approximated as perfectly flat surfaces yielding only specular reflection. In addition, sources at distances much larger than normally taken into account in noise maps might still contribute significantly. Since one of the main reasons for this is computational burden, an efficient engineering model for the diffraction of the sound over the roof tops is proposed, which considers multiple reflections, variation in building height, canyon width, facade roughness and different roof shapes. The model is fitted on an extensive set of full-wave numerical calculations of canyon-to-canyon sound propagation with configurations matching the distribution of streets and building geometries in a typical historically grown European city. This model allows calculating the background noise in the shielded areas of a city, which could then efficiently be used to improve existing noise mapping calculations. The model was validated by comparison to long-term measurements at 9 building facades whereof 3 were at inner yards in the city of Ghent, Belgium. At shielded facades, a strong improvement in prediction accuracy is obtained.

Author

W. Wei

Ghent university

D. Botteldooren

Ghent university

T. Van Renterghem

Ghent university

Maarten Hornikx

Chalmers, Civil and Environmental Engineering, Applied Acoustics

Jens Forssén

Chalmers, Civil and Environmental Engineering, Applied Acoustics

E. Salomons

Netherlands Organisation for Applied Scientific Research (TNO)

Mikael Ögren

The Swedish National Road and Transport Research Institute (VTI)

Acta Acustica united with Acustica

1610-1928 (ISSN)

Vol. 100 6 1098-1111

Subject Categories

Fluid Mechanics and Acoustics

DOI

10.3813/aaa.918789

More information

Latest update

4/18/2018