Study On Nonlinear Behaviors In The Time-domain In Argon Atmospheric Dielectric-barrier Discharges

Presently,Dielectric-barrier discharges(Silent discharges) have a large scale of industrial applications,such as ozone synthesis,pollution control,surface treatment,fluorescent lamp, large flat panel display and etc.Atmospheric discharges controlled by dielectric barriers can save facility and circulating values as well as continuously provide treatment and enhance the production efficiency.This kind of atmospheric discharge has attractive prospects for industry application because they are more uniform than others.As a spatially extended dissipative system with strong nonlinearity,the uniform DBDs principally possess complex temporal nonlinear behaviors such as period doubling bifurcation, quasi-periodicity,and chaos and so on,which have been observed and studied experimentally and numerically in driven or undriven plasmas discharge systems at low pressure.However, there are lots of nonlinear characteristics of DBDs still unknown,for instance,the most studies of atmospheric pressure discharge controlled by dielectric barriers are focused on the single-period discharge characterized by one or multiple current pulses per half cycles of the applied voltage.Present work based on one dimensional hydrodynamics model,simulated the nonlinear behaviors of argon atmospheric dielectric-barrier discharges which generated between two symmetrical parallel electrodes covered with dielectric barrier.And the discharge is driven by sinusoidal voltage.The simulation results show that,as the frequency increasing,the discharge not only can turn into chaotic state through periodic doubling bifurcation,but also can return stable periodic motion from chaotic state through an inverse period-doubling bifurcation sequence. Evolvement of current density together with Poincare section is utilized to show the periodicity of the discharge behaviors.Bifurcation discharges are more sensitive to controlling parameters and easily driven to chaos state.Many periodic windows embedded in chaos,the secondary bifurcation occurring in the periodic windows can also be observed.In period-doubling discharge and in a chaotic state,two different discharge modes,i.e. Townsend and glow modes,can alternatively occur during one circle of the discharge current.Using the same model and numerical simulation method,period-two discharge characteristics in argon atmospheric dielectric-barrier discharges have been investigated during a very broad frequency range from kilohertz to megahertz.The results show that period-two discharges occur under different frequency once other parameters are suitable. And they possess different voltage and current behaviors.The stability of the period-two discharge is associated with the symmetry of the discharge current between positive and negative half cycles.As the frequency is relatively small,the discharge current is not symmetrical and the discharges are not stable.When the driving frequency become large enough and the discharge current becomes highly symmetrical,the period-two discharge can reach to a steady state and can sustain over a broad frequency range.The stable period-two discharges operate in typical glow mode.For high frequency,the temporal profiles of the current and voltage are predominately sinusoidal,no more pulses because the effect of dielectric barrier is faintness under high frequency.Besides,the peak memory voltage and the gas voltage remain relatively unchanged as the frequency increase.