The characteristics of self-pulsing discharges in geometrically similar gaps

Abstract

The characteristics of self-pulsing discharges in geometrically similar gaps are investigated. The validity of the similarity laws for self-pulsing discharges between parallel-plate electrodes is investigated via experiments and fluid simulations. The experimental results reveal that the waveforms of the self-pulsing discharge voltage and current (i.e., the maximum and minimum of the self-pulsing discharge voltages and discharge currents and the pulsing frequency) and the voltage–current curves exhibit scale invariance across geometrically similar gaps. The voltage–current phase loops remain nearly identical when the similarity conditions are met. The simulation results show that the discharge current, electrical potential, reduced electric field, electron temperature, and scaled electron density follow qualitatively to the similarity transformation across the scaled discharge gaps. These findings confirm the validity of similarity laws in the self-pulsing discharge regimes, thereby facilitating the comparison of discharge characteristics across different pressure conditions and dimensional scales. This article extends the applicability of discharge similarity laws to unstable discharge regimes.