Spiral Formation And Evolution In Dielectric Barrier Discharge

The dynamics of spiral patterns have been studied in dielectric barrier discharge at atmospheric pressure in Argon/Air by using water electrodes. The spiral formation has also been simulated by three component reaction diffusion equations.A rich variety of spiral patterns such as single-armed spiral, dipole spirals, target pattern, multiarmed spiral and spiral defect chaos have been observed at high pd value for the first time. The spiral formation and evolution and the core dynamics have been studied under different boundary conditions. In the free boundary condition, the spiral pattern arises when the stripe pattern undergoes core instability or notching instability, in which the notching instability is observed in experiment for the first time. The core of the spiral will drift upward rapidly. In the confined boundary condition, the spiral pattern is formed by sidewall forcing, and the core will meander with a relatively low velocity. The spatio-temporal dynamics of the spiral structure is measured for the luminous feature. Two mechanisms of spiral breakup, core breakup and far filed breakup, have been observed.The dynamics of dislocation have been studied. Dislocation has two fashion of movement: gliding and climbing. When the dislocation and spiral pattern interact each other, the spiral arm will add one their topological charges have the same sign, otherwise, the spiral arm will minus one. The rotation direction of the spiral may change in the transition spiral– target– spiral.The spiral formation has been simulated by using the three-component reaction diffusion equations. The linear stability analysis and the dispersion relation have also been made.