Fig. 1. Schematic diagram of discharge circuit and schlieren system.

Fig. 2. Schematic diagram of actuator layout (unit: mm).

Fig. 3. Discharge characteristics: (a) voltage–current waveform, (b) power waveform.

Fig. 4. Discharge waveforms at different DC voltages: (a) voltage waveform, (b) current waveform.

Fig. 5. Flow field evolution.

Fig. 6. Difference of mean gray value in monitoring area.

Fig. 7. The flow field structure of arc discharge under different pressure: (a) t = 40 μs, (b) t = 440 μs, (c) t = 1080 μs, (d) t = 1680 μs.

Fig. 8. The flow field structure for different DC voltage under ambient pressure of 20 kPa.

Fig. 9. The variation of thermal deposition with pressure.

Fig. 10. The velocity of a shockwave under different pressures.