Study on the effect of porous fence on air quality and traffic noise level around a double-decked road structure

Abstract

Fence for traffic noise control sometimes causes adverse effect on air pollution. Thus in this study, performance of porous fence as a tool for control of both air pollution and noise pollution was evaluated. A two-dimensional numerical model for flow and pollutant concentration and an analytical model for traffic noise were utilized in the analysis of a double-decked road structure with fences only at ground (Case 1) and at both ground and upper deck (Case 2). Porous fences were assumed only at the ground level since the solid fences at the upper deck usually leads to desirable result on air pollution. Effects of the variable porosity on air quality and noise level near road were evaluated. Obtained results showed: (1) flow pattern in leeward of fence was drastically changed at 40-50% porosity in Case 1 and 50% in Case 2. The porosity larger than 40% excluded presence of a circulation behind the fence. (2) Effect of porous fence on air pollution was different in Cases 1 and 2. In Case 1, the porous fence generally resulted in the reduction of air pollution at the ground level; on the other hand, in Case 2, it rather led to increase of the concentration. (3) Traffic noise level was also largely changed by the porosity of the fence; an example of simultaneous evaluation of the effects of porous fence on both air and noise pollution in Case 1 showed that the fence of 60% porosity leads to reduction of air pollution by 20% compared with solid fence case, and reduction of noise pollution by 4-6% in dB compared with no fence case, at 1 m high and 10 m from the road.

Prediction of sound transmission losses for polymer/inorganic particle composites

“…It is generally believed that a noise is recognized as one of components of industrial pollution, and an environmental issue that is a byproduct of technological development in modern society such as machinery, automobile, appliances, and so on. . Hence, how to reduce the noise from has been studied extensively during recent two decades.…”

Evaluation of Pp/Clay Composites as Soundproofing Material

“…It means when sound transfers in media, energy loss and reflected energy must be maximized to minimize the transmitted energy. Therefore, the maximum reflection of incident sound is one of the best ways to increase sound absorbing ability [1][2][3][4][5] . There are lots of attempts to reduce noise pollution by using polymer based composites such as PVC, PP fiber, and polypyrrole nanometer additive [6][7] .…”

Experimental and numerical analysis of the sound insulation property of wood plastic composites (WPCs) filled with precipitated CaCO3

“…Excessive noises can seriously affect people by causing fatigue, reducing working efficiency, and causing health system disorders. Various materials have been investigated as noise barriers (Tokairin and Kitada 2005 ;Mazeaud and Galland 2007 ;Zhang et al 2007 ).…”