Modeling and Analysis of the Effects of Noise Barrier Shape and Inflow Conditions on Highway Automobiles Emission Dispersion

Shaoguang Wang,Xiuling Wang

doi:10.3390/fluids4030151

Abstract

Recent research has suggested that noise barriers have significant impacts on near-road automobile emissions reduction. T-shaped noise barriers have better performance on reducing noise than others, however, their effects on automobile emissions reduction are not clear. In this research, commercial software ANSYS®Fluent 19.2 (Ansys Inc., Canonsburg, PA, USA) was applied to simulate the noise barrier shape and different inflow wind shear condition effects on highway automobiles emission dispersion. Various Reynolds Averaged Navier-Stokes (RANS) models were tested. The realizable k-ε turbulence model was selected to simulate the turbulent flow caused by fast moving vehicles on highway based on the comparison results. A non-reacting species transport model was applied to simulate emission dispersion. Results showed that the T-shaped barrier was able to help reduce highway automobiles emission concentration in downstream areas more than the rectangular barrier. An optimized range of the T-shape was proposed; under the inflow condition without wind shear, the noise barrier shape effects on automobiles emission reduction were not significant.

Highlights

Vehicle emissions on highways can lead to air pollution and some symptoms of disease in people, especially young children, who live in the proximity of heavily trafficked highways [1]
The whole numerical simulation domain is the mixture of carbon monoxide and air
Validation was first conducted for various Reynolds Averaged Navier-Stokes (RANS) turbulence models

Summary

Introduction

Vehicle emissions on highways can lead to air pollution and some symptoms of disease in people, especially young children, who live in the proximity of heavily trafficked highways [1]. Previous research showed that vehicle emissions could cause prematurity and low birth weight among mothers [2] and respiratory problems to residents [3]. Air pollution has been a serious global issue. One major source of air pollutants is vehicle emissions, which contain toxic nitrogen oxides (NOx ), carbon monoxide (CO), and particle matter (PM).

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Results

Conclusion