In this paper, we process images of different patterns with a Fast Fourier Transformation (FFT) to investigate
the spatial development of patterns in dielectric barrier discharge system. A bifurcation scenario from hexagonal
pattern to square pattern is observed under circular boundary as the driving voltage increasing. The spatial
characteristics of hexagonal pattern and square pattern are studied by analyzing their related spatial Fourier spectra.
In addition, a transition from hexagons to squares and a further development of square pattern with dislocation
defect are also researched by analyzing their Fourier spectra.
The images of square pattern, square superlattice pattern, and hexagonal pattern observed in dielectric barrier
discharge are processed to get the exactitude binary images for further investigation. By using spatial correlation function,
it is found that both of square and hexagonal patterns show perfect structures, and the square superlattice pattern exhibits
an interleaving of two perfect squares with the same wavelength including large and small spots respectively.
Furthermore, angular spectral distribution is used to study pattern development. It shows that, square and hexagonal
patterns are formed with single modes respectively, while square superlattice pattern is governed by a three wave
The influence of different water temperatures on temporal behavior of dielectric barrier discharge in argon at
atmospheric pressure is studied by using an experimental device with water electrodes. It is found that, as the applied
voltage increasing, the evolvement of discharge with different water temperatures shows similar behavior spatially if
argon concentrations are same. The corresponding Fourier transformation is obtained by processing patterns images
with computer program based on the Matlab software. The discharge duration of the first current pulse in half cycle of
different voltage polarity is same in discharge if the two electrodes temperatures are same. But it becomes different if
the two electrodes have different temperatures. The discharge moment is always ahead when the low temperature
electrode is an instantaneous cathode. The analysis shows that the water temperature affects the accumulation of wall
charges, resulting in the differences of temporal behavior of discharge.
A honeycomb hexagonal pattern is observed in a dielectric barrier discharge system, which bifurcates from a square
pattern. As the filaments composing the pattern emit visible light, an optical system is specially designed to study the
spatiotemporal dynamics of the honeycomb hexagonal pattern. The light emitted from pattern, one honeycomb-like cell,
filaments in a line of a cell, and a single filament are detected, respectively. The measurement on spatiotemporal
correlation between two different individual filaments is also performed. It is found that the honeycomb hexagonal
patternis an interleaving of three hexagonal sublattices discharging harmonically and subharmonically. It is found
experimentally that the discharge current signals have three pulses in each half cycle of the driven voltage. Its
characteristics are also investigated by measuring FWHMs and peak voltages of the three discharge pulses, as well as the
time intervals between peaks of different pulses, respectively.