Investigation on ignition characteristics of charring conductive polymers stimulated by electric energy

Abstract

The arc ignition based on charring conductive polymers has advantages of simple structure, low ignition power consumption and restart capacity, which bringing it broadly application prospect in hybrid propulsion system of micro/nano satellite. In order to optimize the performance of arc ignition system, it is essential to have a deeper understanding of the ignition processes and ignition characteristics of charring conductive polymers. In this paper, the thermal decomposition, electrical conductivity and thermal conductivity characteristics of charring conductive polymers with different conductive additives and matrix materials were comprehensively evaluated. An experimental investigation was conducted to determine the ignition behaviors and characteristics of different charring conductive polymers in a visual ignition combustor. The experiment result showed that the ignition delay and external energy required for ignition are negatively correlated with voltage and initial temperature of the ignition grain, but positively correlated with oxidizer flow velocity. Compared with charring conductive polymers containing multi-walled carbon nanotube, the ignition delay of charring conductive polymers with carbon black is significantly higher and the pyrolysis time is relatively longer. However, the ignition and initial flame propagation of charring conductive polymers with carbon black is more violent and more inclined to carbon particle ignition. Finally, the restart characteristic of different charring conductive polymers was studied. The ignition delay and external energy required for ignition of different charring conductive polymers all reduced with the increasing of the number of ignitions. However, the ignition characteristics would not change a lot after repeated ignition.