CFD modeling vehicle exhaust dispersion in complex urban areas

Abstract

This work proposes a CFD model for predicting vehicle combustion exhaust propagation in the
micro-scale approach, in which the buildings and street canyons in urban areas are accurately represented in
computational domain. The pollution dispersion is calculated with the advection-diffusion-reaction equation.
The Reynolds averaged Navier-Stokes equations are numerically solved for wind flows. The movement and
the heat release rate of the vehicles on the roads are considered as sources for environmental turbulent energy.
Two formulations are proposed to represent the light and heavy traffic, respectively. The pollution sources
coming from vehicle emissions on the streets may be varied unsteadily, which reflects the movement of
vehicles.