Study of high-power breakdown accompanied by sliding discharge mode in a three-dimensional sliding arc plasma igniter

Abstract

In order to improve the ignition reliability of a small-thrust rocket engine, a three-dimensional sliding arc igniter discharge characteristic research experimental system was constructed. The work gas flow rate and excitation parameters were changed, the plasma discharge characteristic and spectral characteristic parameters were measured, and the characteristics of the igniter discharge modes were investigated. The influence of the excitation parameters on the discharge modes was explored, and the effect of the discharge modes on the ignition performance of the igniter was analyzed as well as the mechanism of the discharge modes. The results show that the igniter has three different discharge modes during the discharge process, i.e., breakdown with sliding mode, high-power breakdown with sliding mode, and the transition state between the two modes, the shift of the discharge mode is mainly affected by the excitation power, and the igniter is in the breakdown with sliding mode when the excitation power is low, and in the high-power breakdown with sliding mode when the power is high. High-power breakdown with sliding mode has both breakdown with sliding and stable sliding characteristics in the early stage of the sliding arc movement for the breakdown with sliding and then transformed into sliding. Compared with the breakdown with sliding mode and high-power mode, the sliding arc discharge area is wider, the concentration of O * than the breakdown with sliding mode increased by 2.86 times, the electron temperature increased by 31.76%, and it can significantly improve plasma ignition effect, reduce the activation energy and enhance the performance of the igniter.