声振荡作用下推进剂铝颗粒团聚特性实验研究

Agglomeration characteristics of aluminum in solid propellantsunder acoustic oscillation

为获得压强振荡对推进剂燃烧表面铝颗粒团聚特性的影响,建立了声振荡作用下铝颗粒团聚特性实验测量装置和方法,采用高速显微成像技术和激光全息技术同步测量的方法,对HTPB四组元推进剂在有、无声振荡作用下的铝颗粒团聚特性进行了实验研究。研究结果表明,在340 Hz声振荡作用下,铝颗粒火焰呈现与声振荡频率相一致的周期性摆动,颗粒微观形貌发生明显的形变;受声场力的作用,小尺度颗粒(40~80μm)团聚作用减弱,中等尺度颗粒(100~260μm)团聚作用加强,且更容易发生融合等现象,从而改变了推进剂燃烧表面及近表面铝团聚颗粒粒度分布(0~3 mm),团聚粒度及团聚分数均增加。所建立的实验方法可为研究压强振荡作用下推进剂铝团聚特性提供有效的实验技术和数据参考。

To obtain a thorough understanding of the impacts of acoustic oscillation on aluminum agglomeration behaviors,agglomeration processes,and particles size distribution,a synchronous diagnostic method using high-speed microscopic imaging technology and digital in-line holography is adopted.The results show that,under acoustic oscillation(340 Hz),the flame of particles was periodically fluctuated with acoustic pressure oscillation in almost the same frequency,and the morphology of particles is obviously deformed.Acoustic oscillation inhibits the agglomeration of small size particles(40-80μm),but promotes the agglomeration and mergence of medium size particles(100-260μm).Consequently,there is a significant difference in the particle size distribution of aluminum particles(0-3 mm).The average mass particle size,the average agglomerated particle size and agglomeration fraction increased.The method established in this paper provides an effective means and experimental data reference for the research of agglomeration characteristics of aluminum in solid propellants under pressure oscillation.