Modeling and simulation of air pollutant distribution in street canyon area with Skytrain stations

Suranath Chomcheon,Xiangyu Ge,Nathnarong Khajohnsaksumeth,Benchawan Wiwatanapataphee

doi:10.1186/s13662-019-2382-z

Abstract

This paper focuses on effects of the wind flow velocity on the air flow and the air pollution dispersion in a street canyon with Skytrain. The governing equations of air pollutants and air flow in this study area are the convection–diffusion equations of species concentration and the Reynolds-averaged Navier–Stokes (RANS) equations of compressible turbulent flow, respectively. Finite element method is utilized for the solution of the problem. To investigate the impact of the air flow on the pattern of air pollution dispersion, three speeds of inlet wind in three different blowing directions are chosen. The results illustrate that our model can depict the airflows and dispersion patterns for different wind conditions.

Highlights

There are many forms of pollution, including air, water, thermal, noise, soil contamination, etc. [1, 2]
As experimental studies cannot illustrate the pattern of pollutant dispersion accurately, numerical models have been used as a main tool over the last few decades to investigate the local sources of air pollution in street canyon environment under several aspects such as the presence of vegetation [11, 12] and dust [13], the surrounding airflow, and air pollutant dispersion [14,15,16,17,18,19,20,21,22,23,24]
We investigate the effect of wind velocity on dispersion pattern of the trafficrelated air pollution in the street canyon with Skytrain

Summary

Introduction

There are many forms of pollution, including air, water, thermal, noise, soil contamination, etc. [1, 2]. In 2011, Liu proposed two Chomcheon et al Advances in Difference Equations (2019) 2019:459 numerical models to predict vehicle exhaust dispersion in urban areas with or without a wind field [25] In his model, the effect of building and street canyon configuration and the turbulent energy produced by moving vehicles on the pollutant propagation were investigated. A few years later in 2014, numerical investigations on pollutant dispersion in street canyons with emission sources located near the ground level were performed by Madalozzo et al using the pseudo-compressibility hypothesis of mass conservation, the Navier–Stokes equations, energy equation, and pollutant transport equation [26] Their results show that temperature and street-canyon geometry affect both the wind flow patterns and pollutant concentration.

Finite element formulation

Conclusion