基于高速离轴全息可视化方法的Al/AP/HTPB推进剂燃烧性能研究

Study on the Combustion Characteristics of Al/AP/HTPB Propellant Based on High-speed Off-axis Holographic Visualization

为了探究金属颗粒燃烧的复杂变化过程,搭建了25kHz高速数字离轴全息成像系统,对Al/AP/HTPB推进剂燃烧过程中颗粒的典型现象进行了时间分辨三维可视化研究;通过三维可视化研究分析了推进剂燃烧中金属铝颗粒燃烧典型现象,其中包括燃烧过程中推进剂燃面颗粒的剥落现象、颗粒/颗粒团的微爆炸现象、以及燃烧颗粒存在的尾流与火焰面现象,并且通过数字离轴全息技术对观测到的铝颗粒进行了时间分辨的三维重建。结果表明,离轴全息技术消除了孪生像的干扰,可以获得清晰的颗粒重建图像,并且其独立配置的参考光在很大程度上消除了火焰对光传播的影响,有效地抑制了颗粒周围折射率急剧变化所带来的像差。表明高速数字离轴全息三维成像技术在固体推进剂燃烧可视化诊断方面具有较强的实用性,并具有广阔的应用前景。

In order to investigate the complex combustion process of metal particles,a 25kHz high-speed digital off-axis holographic imaging system was built to study the time-resolved three-dimensional visualization of typical phenomena of particles during Al/AP/HTPB propellant combustion.The typical combustion phenomena of Al particles in propellant combustion were analyzed by 3D visualization,including the flaking of particles on the combustion surface of propellant,the micro-explosion of particle clusters,and the existence of wake flame surface of burning particles.Time-resolved three-dimensional reconstruction of the observed aluminum particles is performed by high-speed off-axis holography as well.The results show that off-axis holography technique eliminates the interference of twin images and can obtain clear reconstructed images of particles.Its independently configured reference light largely eliminates the influence of flame on light propagation and effectively suppresses the aberration caused by the sharp change of refractive index around the particles.The high-speed off-axis holography has strong practicality and broad application prospects in the visualization and diagnosis of solid propellant combustion.