Numerical modelling of negative discharges in air with experimental validation

Abstract

Axisymmetric finite element models have been developed for the simulation of negative discharges in air without and with the presence of dielectrics. The models are based on the hydrodynamic drift-diffusion approximation. A set of continuity equations accounting for the movement, generation and loss of charge carriers (electrons, positive and negative ions) is coupled with Poisson's equation to take into account the effect of space and surface charges on the electric field. The model of a negative corona discharge (without dielectric barriers) in a needle-plane geometry is analysed first. The results obtained show good agreement with experimental observations for various Trichel pulse characteristics. With dielectric barriers introduced into the discharge system, the surface discharge exhibits some similarities and differences to the corona case. The model studies the dynamics of volume charge generation, electric field variations and charge accumulation over the dielectric surface. The predicted surface charge density is consistent with experimental results obtained from the Pockels experiment in terms of distribution form and magnitude.

Numerical Simulation of the Characteristics of Electrons in Bar-plate DC Negative Corona Discharge Based on a Plasma Chemical Model

“…The electron energy flux at the cathode and the anode is: electron density at t=0. The initial condition has been confirmed to only speed up the pulse formation and not to change the discharge characteristics [25,36].…”

“…These transport coefficients of electrons are obtained from solving the Boltzmann equation [25].The streamer discharge in air in highly overstressed gap is very fast (several nanoseconds). On the several nanoseconds time scale, the diffusion and mobility phenomenon of heavy species (ions and neutral particles) have almost no influence on the discharge propagation.…”

Ion-impact secondary emission in negative corona with photoionization

“…The governing equations are expressed as follows by adding background ionization and photoionization term based on Tran's experiment. 24 ∂c e ∂t = c e α|W e | − c e η|W e | − c e c p β ep −∇ · (c e W e − D e ∇c e ) + S ph + S 0…”

Space and Time Domain Finite Volume Method for Numerical Simulation of Negative Corona Discharge in Air

“…v e , v p , and v n are the drift velocities of electrons, positive ions, and negative ions, which can be obtained by [22]: 1 7 6 3.63 10 exp( 1.68 10 / ), 4.56 10 / 7.36 10 exp( 2 10 / ), 4.56 …”