Modeling of a Novel Large-scale Electrohydrodynamic Vortex Flow Induced by Variation in Current Density for Drag Reduction

ERIC MONSU LEE, Northern Illinois University

     Abstract Number: 47
     Working Group: Control and Mitigation Technology

Abstract
The recent emphasis on environmental justice by the U.S. EPA has motivated the aerosol research community to develop innovative and cost-effective particulate matters (PMs) control technologies for subpopulations who are frequently exposed to indoor PMs. PM collection by electrostatic precipitation (ESP) has been proposed for indoor usage because it provides advantageous features over conventional fabric filters, such as lower energy consumption and being filterless. However, further research is needed before ESP can be used in indoor spaces, as ESP involves corona discharge that generates trace amounts of ozone and the particle collection efficiency for fine and submicrometer particles is highly variable due to a lower rate of particle charging. The ultimate goal for the present study is to address the issue of low collection efficiency for submicrometer particles by using electrostatic particle agglomeration. A novel large-scale electrohydrodynamic (EHD) vortex flow was previously discovered in the streamwise direction of a cylindrical ESP due to variation in current density. The objective of this modeling study is to characterize the large-scale EHD vortex flow for drag reduction and its implications on particle collection. The numerical model developed by COMSOL Multiphysics® solves the large-scale EHD vortex flow by coupling electrostatic physics with RANS k-ε turbulence flow physics, involving three numerical domains. The present study discovered that the large-scale EHD vortex flow can modify the turbulent boundary layer and result in a reduction in viscous drag near the collection electrode that can potentially lead to improved particle collection involving electrostatic particle agglomeration.