Numerical simulation of particle formation and evolution in a vehicle exhaust plume using the bimodal Taylor expansion method of moments  

作　　者：Shuyuan Liu Tat Leung Chan Huijie Liu 

机构地区：[1]Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China

出　　处：《Particuology》2019年第2期46-55,共10页颗粒学报（英文版）

摘　　要：The bimodal Taylor expa nsion method of moments (B-TEMOM) model scheme was developed to simulate the formation and evolution of vehicle exhaust particles. Two independent types of log-normal particle size distributions were selected in the B-TEMOM model scheme, comprising large and small particles to represent background (i.e., the surrounding environment) and vehicle exhaust particles, respectively. Concentration distributions of exhaust and background particles derived using this model scheme were verified against results from a moving secti onal method and the bimodal quadrature method of moments, showing excellent agreement. The effects of vehicle tailpipe ex 让 cond 让 ions (e.g., exhaust particle concentrations and velocity), sulfurcontent, and relative humidity on the evoluti on of particles were investigated numerically. Both two-dimensional and three-dimensional numerical simulations showed that tailpipe exit velocity and relative humid让y did not greatly affect the steady-state concentrations or the diameters of particles in urban atmospheres. Although an increase in sulfur content had little effect on the particle concentration, it led to background particles with larger geometric average diameter entering the environment. This coupled CFD-B-TEMOM numerical model provides a simple but accurate and efficient method for studying bimodal aerosol dynamics.

关 键 词：VEHICLE exhaust particles BIMODAL TAYLOR expansi on method of MOMENTS Homogeneous nucleation COAGULATION Tailpipe EXIT velocity Sulfur content and ambient relative humidity 

分 类 号：O3[理学—力学]