Fig 1.
Annular SDBD under water-covered condition: (a) Schematic diagram of SDBD structure under water-covered condition, (b) Experimental equipment and measuring system.
Fig 2.
Typical discharge image (d = 2 mm): (a) 100 pulse superimposed discharge images, (b) Single pulse discharge image, (c) Discrete micro-discharge channels 0~9 processed by gray scale in single pulse discharge image, (d) Different regions in 800 pulse discharge image.
Fig 3.
Typical current waveform of annular SDBD under no water-covered and water-covered condition (d = 2 mm).
Fig 4.
Fast Fourier transform of current of annular SDBD under no water-covered and water-covered condition.
Fig 5.
Gray value change of micro-discharge channels in single-pulse discharge image: (a) Grayscale curve of micro-discharge channels in single-pulse discharge image, (b) Mean of micro-discharge channels gray value of single pulse discharge image.
Table 1.
Values of M and Std in each area.
Fig 6.
Diagram of water droplet deformation after the discharge of SDBD.
Fig 7.
Deformation factor K of water droplet at different voltage amplitudes and water-covered positions.
Table 2.
Conductivity parameter of different droplet.
Fig 8.
Discharge images of droplets with different conductivity.
Fig 9.
Discharge gray value change under the attachment of droplets with different conductivity: (a) Grayscale intensity Mean in the first stage of discharge, (b) M and Std of overall grayscale values of SDBD.
Fig 10.
Variation of current amplitude and discharge initial voltage: (a) Changes in current amplitude under different conductivity, (b) Changes in discharge initial voltage with the same volume under different conductivity, (c) Changes in discharge initial voltage for different volumes with the same conductivity.
Fig 11.
Contour and curve of external electric field of annular SDBD under water covering condition (d = 2 mm): (a) Contour of annular SDBD electric field under no water-covered condition, (b) Contour of annular SDBD electric field under water-covered condition, (c)Curves of variation of external electric field with r under different z values.
Fig 12.
Schematic diagram of electric field generated by water droplet polarization.
Fig 13.
Schematic diagram of the discharge development process.