Sound propagation above periodic & aperiodic rough surfaces
Invited paper
The Open University
Tuesday 2 june, 2015, 17:20 - 17:40
0.8 Rome (118)
Abstract:
Transport noise is an ever present concern in urban areas affecting quality of
life for millions of people. Limitations on space and aesthetic considerations
limit the choice of noise control measures. Roadside areas and surfaces
offer an opportunity to be utilised for this purpose.
It has been shown that artificially making a rigid, flat surface rough results
in broadening the destructive interference between direct and ground-reflected
sound waves and reduces its centre frequency. This paper investigates effect
of aperiodic and period patterns of roughness and also the role of vacancies
(missing elements) in the pattern on optimising the overall insertion loss
from the surface. Model measurements to test these results are also
reported.