@article {Van der Eerden:2019:0736-2935:399, title = "The barrier effect of roadside diffracting elements for standard noise calculations", journal = "INTER-NOISE and NOISE-CON Congress and Conference Proceedings", parent_itemid = "infobike://ince/incecp", publishercode ="ince", year = "2019", volume = "259", number = "9", publication date ="2019-09-30T00:00:00", pages = "399-406", itemtype = "ARTICLE", issn = "0736-2935", url = "https://ince.publisher.ingentaconnect.com/content/ince/incecp/2019/00000259/00000009/art00063", author = "Van der Eerden, Frits and Brouns, Eef and Eisses, Arno and Van Vliet, WillemJan", abstract = "By using elements with quarter-wavelength resonators of different depths alongside a road, noise can be diffracted upwards to create a zone of noise reduction behind these elements. Measurements at a short distance, up to 15 meters, have proven that a noise reduction up to 4 dB(A) can be achieved. The noise reduction at long distance, up to 600 meters, was calculated numerically by combining a finite element model (FEM) and a parabolic equation model (PE), taking a downwind condition into account. These results are used to design an engineering approach that represents a barrier effect. This approach can be implemented in the standard noise calculation models, such as the Dutch national model or the ISO 9613-2 standard. The steps that are used for this engineering approach are explained. This involves the measurement of the intrinsic characteristics of the diffracting elements and empirical relations that use these characteristics.", }