JAUE2017-085: Dynamics Evolution of Aerosol Particles in a Vehicle Exhaust Plume

Abstract

The dynamics evolution of aerosol particles in terms of time, space and property in the near field of a 
vehicle exhaust plume is modeled by coupling the Eulerian-Lagrangian model and population balance model. 
The coupling scheme is characterized by high-resolution particle tracking using the Multiphase 
particle-in-cell method (MP-PIC) and the high precision of the particle size spectrum by solving the 
population balance equation (PBE) with the quadrature method of moments (QMOM). Firstly, the 
gas/particle phase flow field and spatial distribution characteristics of particles at different vehicle’s speeds 
(i.e., 0 km·h-1, 10 km·h-1 and 30 km·h-1) are studied. Then, the distribution of moments (i.e., number 
concentration, volume concentration, average diameter) of particles are analyzed. The results suggest when 
the vehicle is stationary, serious particle accumulation occurs in the vehicle’s exhaust exit; the distribution of 
particle number concentration is larger locally, and the maximum concentration occurs at the exit. With the 
increase of the vehicle’s speed, the exhaust is usually entrained, making the maximum local particle 
concentration decrease. The Sauter mean diameter of the particles is far larger at 10 km·h-1 than at 30 km·h-1, 
and the particles are more likely to spread in space when the vehicle runs at a high speed.