Field performance of a noise barrier

The insertion loss of screens under the influence of wind

“…For downwind the results show that the insertion loss fluctuates around zero. This is in agreement with findings of Scholes et al 16 who measured the influence of screens ͑full scale measurements͒ and who found that in a downwind situation the insertion loss was not always positive.…”

“…In practice the insertion loss will often be influenced by temperature gradients and wind, including turbulence effects, but it appears that only few studies of this exist. [15][16][17][18][19] In the present work a screen on a finite impedance surface representative of grass-covered ground is investigated experimentally and theoretically under the influence of wind. Upwind as well as downwind conditions are investigated.…”

A comparative study of the physical mechanisms related to highway noise barrier insertion loss : measurements versus modeling assumptions.

“…Comparing the frequency spectrum of reflection theory of a point source of HNP 1.0 with that ofTNM 2.5 and the measurements by Parkin and Scholes (Parkin, 1965) 2. Comparing the frequency spectrum of insertion loss of a point source of HNP 1.0 with that ofTNM 2.5 and the measurements by Scholes (Scholes, 1971) 3. Comparing the insertion loss at receiver points by a line source ofHNP 1.0 with that of TNM 2.5 and STAMINA 2.…”

“…The second verification is to compare ground effect with the measurements by Parkin and Scholes over grassland (Parkin, 1965). The third verification is to compare the insertion loss of a noise barrier by Scholes, also over grassland (Scholes, 1971). Since TNM validations are mainly based on the above three verification cases of point source, HNP will also provide detailed comparisons for all these cases.…”

“…conducted TNM validation by comparing the TNM predicted insertion loss with the measured barrier insertion loss of Scholes (Scholes 1971) using the point source. The comparisons were made with a limited set of measured data with the following geometry: source height of 0.7 m (2.3 ft); barrier heights of 1.8 m (6 ft) and 4.9 m (16 ft); microphone heights of 1.5 m (5 ft), 3 m (10 ft), 6 m (20 ft) and 12 m (40 ft), source-to-barrier distance of 10 m (33 ft); and barrier to receiver distance of30 m (100 ft).…”