Numerical Study On The Optimization Of Boundary Conditions And The Long Pulsewidth Effects Of Atmospheric-Pressure Pulsed Dielectric Barrier Dischtarge In Argon

The non-thermal plasma presents broad prospects of application and has been used in many fields due to its unique advantages.It has become an active field of research to generate homogeneous non-thermal plasmas through gas discharge at atmospheric-pressure.Dielectric barrier discharge(DBD)is thought to be an effective solution to obtain atmospheric-pressure non-thermal plasmas and has attracted extensive attention in recent years.With the development of power source technology,the excitation of atmospheric-pressure DBD has evolved from the traditional sinusoidal voltage source to the pulsed voltage source.The atmospheric-pressure DBD driven by the high-voltage pulses with repetitive frequency is of the excellent performances from both pulsed discharge and DBD,and it is an ideal way to generate the highly reactive and homogeneous non-thermal plasmas at atmospheric-pressure.In particular,the characteristics and advantages of atmospheric-pressure pulsed DBD can well work in concert with the practical requirement in the applications of non-thermal plasmas,which is not only suitable for large-scale industrial applications of non-thermal plasmas,but also provides new direction and content in the study on gas discharge and discharge plasmas.In spite of the reported studies on atmospheric-pressure pulsed DBD,there are still a large number of questions left open,such as the mechanisms and discharge characteristics of atmospheric-pressure pulsed DBD.This dissertation presents an investigation on the optimization of the boundary conditions involved in one-dimensional fluid model simulating atmospheric-pressure pulsed DBD and on long pulsewidth effects on the pulsed DBD,and includes the following contents and results:1.The boundary conditions included in the one-dimensional fluid model are processed strictly and optimized in physics.The discharge currents are calculated by use of the numerical simulations adopting the ordinary boundary conditions and optimized boundary conditions,respectively,and compared with the experiments.The comparison shows that at different pulsewidths,the optimized boundary conditions make the calculated discharge currents coincide with the experiments better.2.Based on the established fluid model,the peak values of discharge currents,the spatiotemporal averaged density of each particles and the axial distribution of electric field intensity at the long pulsewidths and at the corresponding short pulsewidths have been calculated and compared,respectively.The generation reaction pathways of argon particles are analyzed and the corresponding contributions are calculated.The present study shows that in these two cases,i.e.long pulsewidths and the corresponding short pulsewidths,the calculated results are in exchange symmetry and the discharges are in the atmospheric-pressure glow discharge mode.In addition,the effects of pulsewidth on the reaction pathway contributions are very small.