Aerosol nano-particle charger simulations and optimizations


1 School of Engineering and Science, Sharif University of Technology, Kish, Iran.

2 School of Mechanical Engineering, Sharif University of Technology, Tehran, P.O. Box 11155-9567, Iran.


Size distribution of aerosol particles is prevalently obtained through electrical characterization techniques and study of charged particles' dynamics in the presence of electric eld. In this work, a wire-cylinder corona charger is presented, redesigned, and aerodynamically optimized. An initial 2D axisymmetric geometry of the charger was employed for the simulations using the Computational Fluid Dynamics (CFD) commercial code FLUENT 6.3.26. Through successive attempts, a new geometry was obtained by streamlining the walls to eliminate the undesired vortices produced in the flow eld of the previous ones. The process optimized the charger by minimizing losses and dilutions of the particles. For electrical simulations of the charger, a new numerical algorithm was designed based on the steady-state corona discharge to work with segregated solvers to satisfy governing equations. The algorithm was validated using a one-dimensional semianalytic solution of corona discharge. Tracing particles for the optimized geometry, the percentage of losses was calculated 6%, whereas the loss in the old geometry was more than 30%. The average charge and charge distributions induced on particles were also calculated with evaluation of the residence times in the charger.