DYNAMICS IN DBDS FOR PLASMA REMEDIATION OF TOXIC GASES
Xudong "Peter" Xu and Mark J. Kushner
DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING
University of Illinois at Urbana/Champaign
Dielectric barrier discharges (DBDs) are attractive plasma sources for remediation of toxic gases, such NxOy, SO2, and VOCs, due to their ability to operate at atmospheric pressure with moderate applied voltage. In this project, the reaction mechanisms and the plasma hydrodynamics in DBDs have been investigated.
1-d and 2-d plasma chemistry and hydrodynamic models have been developed to investigate DBDs. These simulations include circuit models, solutions of Boltzmann's equation for the electron energy distribution, plasma chemistry modules, and solution of the compressible Navier-Stokes equations.
Carefully crafted square wave pulses are able to obtain a second discharge pulse which discharges the dielectric following the first discharge pulse, thereby doubling the the energy deposition. The expansion of the microstreamer is, in large part, determined by the radial charging of the dielectric, and can be influenced by surface dielectric surface conductivity. Closely spaced microstreamers can interact on 10s ns - 100s ms time scales. In the results shown below, the electron density is plotted for a 40 ns, 11 kV pulse in pure nitrogen at 1 atm. 4 microdischarges expand to interact with each other.
Electron Density (for 40 ns voltage pulse of 11 kV, in pure nitrogen, in 1 atmosphere)