基于大沸点差的多元镁基金属对推进剂燃面铝团聚的影响机制

Aluminum agglomeration on combustion surface of solid propellant has a great effect on motor’s specific impulse and safety，improving combustion efficiency of aluminum is one of most important mission in the field of combustion of solid propellant. How to suppress the aluminum agglomeration without losing specific impulse of the propellant is a major scientific problem that needs to be solved. Adding multi-metal with a large disparity in boiling points into solid propellants is one of the important ways to inhibit the aluminum agglomeration thanks to microexplosion and dispersive boiling on burning surface, while metal’s composition and structure directly affect the energy of the propellant and its inhibition result. The purpose of this program is to explore impact mechanism of magnesium based multi-metal’s composition and structure on aluminum agglomeration. Metal fuel with series of components and structures can be designed and prepared at first. Process and mechanism study of energy release of magnesium based multi-metal can offer a theoretical basis to restrain agglomeration of aluminum. Mechanism analyzing of magnesium based multi-metal’s effect on aluminum agglomeration can be gotten from two aspects: 1) studying of combustion property, extinction surface and combustion condensed products (CCPs) of solid propellant loaded with magnesium based multi-metal; 2) observation of residence time and spatial distribution of metal particles on burning surface. This study could be helpful for providing an innovative path to investigate the inhibition of aluminum agglomeration. Research results show great academic significance and applicable potential.

推进剂燃面铝团聚燃烧严重影响发动机的比冲和安全性，抑制铝团聚、提高铝粉的燃烧效率是含铝推进剂燃烧领域重要研究任务之一。如何有效抑制推进剂燃面的团聚且不牺牲推进剂的能量是当前该领域研究的难点和热点。添加基于大沸点差的多元金属并在推进剂燃面处发生微爆轰和分散沸腾，是抑制推进剂燃面铝团聚燃烧的重要途径之一，多元金属的组成与结构直接影响推进剂的能量和其对铝团聚燃烧的抑制效果。本项目针对推进剂对能量和安全性要求，拟通过机理实验和理论分析相结合，设计并调节基于大沸点差的多元镁基金属燃烧剂的组成与结构，阐明燃烧剂的释能过程与机理，获得推进剂燃面铝的停留时间与空间分布规律，结合含多元镁基金属推进剂的燃烧特性，熄火端面和燃烧残渣的定性、定量分析，揭示基于大沸点差的多元镁基金属燃烧剂的组成与机构对推进剂燃面铝团聚燃烧的影响机制。该项目对丰富推进剂燃烧机理，提高发动机的比冲和安全性具有重要意义。

推进剂燃面铝团聚燃烧严重影响发动机的比冲和安全性，抑制铝团聚、提高铝粉的燃烧效率是含铝推进剂燃烧领域重要研究任务之一。如何有效抑制推进剂燃面的团聚且不牺牲推进剂的能量是当前该领域研究的难点和热点。本项目基于大沸点差的多元金属在推进剂燃面处会发生微爆轰和分散沸腾，并可较好抑制推进剂燃面铝的团聚这一设想，开展了二元和三元镁基多元金属的设计和制备，分析了多元金属的组成与结构对其热性能、燃烧焓和点火燃烧过程的影响，获得了多元金属对推进剂燃烧性能的影响规律。研究表明，球型AlMg和AlMgZr相对于Al对HTPB推进剂燃速的促进作用更大，其对推进剂的火焰结构和燃速压力指数影响都不大。AlMg和AlMgZr都可显著减小HTPB推进剂的凝聚相产物尺寸，且铝基多元金属与传统的微米铝粉配合使用时效果最好。AlMg和AlMgZr对推进剂中铝粉燃烧效率的提高也有显著的作用，Al和Mg之间的大沸点差使其在推进剂燃面处可能发生分散沸腾和微爆轰，这可能是其抑制推进剂燃面铝团聚燃烧，并提高含铝推进剂中铝粉燃烧效率的重要原因。项目提出了抑制HTPB基推进剂燃面铝团聚的新方法，有望成为提高含铝推进剂中铝粉燃烧效率和固体发动机安全性的有效途径，为后续相关研究奠定了基础。