Numerical Simulation of Brownian Collision and Coagulation of Nanoparticles in a Tank

Behtash Tavakoli, GOODARZ AHMADI

Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, NY 13699, USA

     Abstract Number: 777
     Last modified: May 14, 2010

Abstract
Volatile organic hydrocarbons especially terpenes can react with indoor ozone and affect the environment and human health. The concentration of VOCs in indoor air is commonly two to five times greater than in outdoor air because of the materials used in buildings and human activities. To simulate indoor pollution, the nucleation, coagulation and growth of nanoparticles in a tank are studied in this paper. alpha-Pinene, as a volatile organic component, and ozone are injected constantly to a tank of air with the volume of 2.48 m$^3. The fans embedded inside the tank mix the air with the components and make it homogeneous. It is assumed that the density of the particles is constant, and they coagulate due to collision, so the total volume of new particles is equal to the summation of the volumes of the smaller particles that are collided. In addition, the Eulerian approach is used by implementing the Smoluchowski model to study the concentration distribution of particles between 50 to 250 nanometers. The concentration of 50 nanometer particles has a sharp increase at the beginning of the process, but then it decreases while the concentration of larger particles are increasing in transient interval time, and finally they reach to the steady state condition in which the concentration of particles does not change by time. The results are compared with the experimental data and discussed.