AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Simulation of Particle Charging and Transport in Corona-induced Electrohydrodynamic Flows
HUAYAN LIANG, Pramod Kulkarni, Lina Zheng, Milind Jog, Centers for Disease Control and Prevention, NIOSH
Abstract Number: 736 Working Group: Aerosol Physics
Abstract We present computational simulation of fluid flow, particle transport, and electrical charging in electrohydrodynamic (EHD) flows in electrical coronas created by a coaxial system of electrodes, with application to aerosol microconcentration. The simulated system involves a set of coaxial electrodes separated by few millimeters, one held at high potential and the other grounded. The particles acquire charge in the corona discharge created around the energized electrode and subsequently collected on the ground electrode from a coaxial flow. This allows efficient aerosol collection on the tip of the electrodes for subsequent analysis by microscale spectroscopies.
The EHD flow of electrically neutral gas is caused by the momentum exchange with the high velocity ions generated in the corona. The simulation, to solve coupled momentum and charge transport, and electrostatics were developed to account for movement of neutral gas species, distribution of charge and electric field, and fluid dynamics in this system using COMSOL multiphysics software. Particle transport was simulated using Brownian dynamics simulation, accounting for appropriate local flow and electrical field. Diffusion charging of particles was modeled to probe the evolution of particle charge during its transport. Details of simulation approach will be presented. Simulations were used to determine collection characteristics of this system as a function of operating parameters such as flow rate, corona current, particle size, and electrode diameter. Comparison with experimental results will be presented and discussed.