Abstract: Using CO₂ laser，high-speed camera and IR thermograph，the ignition and combustion process and the surface temperature distribution of NEPE propellant under laser irradiation were studied. The influence of laser heat flux on the ignition delay time and the dynamic response of NEPE propellant after unloading laser were analyzed. Results show that the ignition delay time tends to decrease with the increase of laser heat flux. When the heat flux is less than 6.7×105W·m-2，the ignition delay time decreases fast with the increase of laser heat flux，but varies little when the heat flux is greater than this value. Laser irradiation had a significant effect on the combustion of NEPE propellant，the brighter flame，the more sparks and the higher temperature of the propellant surface are presented. After the laser unloading，the surface temperature of the propellant does not decline immediately，but falls rapidly after a short delay，and then shows a small rise slowly.

Key words: Solid propellant；Laser irradiation；Ignition delay；Propellant surface；Dynamic response

摘要： 采用CO₂激光器、高速摄像机和红外热像仪等设备研究了NEPE推进剂激光辐照下点火燃烧过程和推进剂表面温度分布，分析了激光热流密度对点火延迟时间的影响以及NEPE推进剂对激光卸载的动态响应。结果表明:增大激光热流密度可以减小点火延迟时间，当热流密度小于6.7×105W·m-2时，点火延迟时间随热流密度的增大而显著减小，而热流密度大于该值时，点火延迟时间随热流密度的增大而变化微小。激光辐照对NEPE推进剂的燃烧有显著影响，使火焰明亮并伴有大量火花，推进剂表面的温度大大提高。激光卸载后，推进剂表面温度并未立即下降，而是在短暂的迟滞后跌落，随后又出现小幅度的缓慢上升。

关键词: 固体推进剂；激光辐照；点火延迟；推进剂表面；动态响应