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A scale model study of parallel urban canyons

Maarten Hornikx (Institutionen för bygg- och miljöteknik, Teknisk akustik, Vibroakustik) ; Jens Forssén (Institutionen för bygg- och miljöteknik, Teknisk akustik, Vibroakustik)
Acustica Acta-Acustica (1610-1928). Vol. 94 (2008), 2, p. 265-281.
[Artikel, refereegranskad vetenskaplig]

Shielded urban areas are of importance regarding urban citizens’ annoyance and adverse health effects related to road traffic noise. This work extends the existing knowledge of sound propagation to such areas by a scale model study, rather than by model calculations. The scale model study was executed for two parallel urban canyons at a 1 to 40 scale, with a point source located in one canyon. Cases with acoustically hard façades and absorption and diffusion façade treatments were in vestigated. To correct for excess air attenuation of the measurements, a wavelet-based method has been applied. The measurement results in the shielded canyon show that, in contrast to the directly exposed street canyon, the levels and the decay times are quite constant over the length of the canyon. The energy-time curve in the shielded canyon is characterized by a rise time, which can be related to the sound pressure level. The rise times and decays can be explained by separate reflection, diffraction and diffusion processes. A closed courtyard situation enlarges the level difference between acoustically hard façades and applied façade absorption or diffusion treatments at both the directly exposed and shielded side. A comparison between measurements with two different diffusion mechanisms, horizontal and vertical diffusion, reveals that vertical diffusion yields lower levels at the shielded side compared to horizontal diffusion for the investigated situations.

Denna post skapades 2008-04-07. Senast ändrad 2014-12-12.
CPL Pubid: 69867


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Institutioner (Chalmers)

Institutionen för bygg- och miljöteknik, Teknisk akustik, Vibroakustik



Chalmers infrastruktur