推进剂中燃烧铝滴直径分布和聚集状态的研究

本文给出了含铝推进剂燃烧时,气相中燃烧铝滴的直径大小与分布,讨论了配方中氧化剂粒度和铝粉粒度对铝的凝聚程度的影响。实验表明,由粗氧化剂组成的推进剂其燃烧时铝的凝聚是很明显的;并且,对应于相同的粗氧化剂,细铝粉比粗铝粉更易凝聚。实验结果支持复合推进剂中铝凝聚的“口袋模型”。本文还用显微密度分析方法对铝的凝聚燃烧机理进行探讨,发现有三种不同类型的光密度分布曲线,文中称之为液滴型,微滴型和液—汽过渡型,它们分別对应于铝的一种聚集状态。此外,还有一种在底片上无铝亮条出现的称之为气相型,它们的燃烧效率是依次升高的。

RESEARCH ON DISTRIBUTION OF SIZE AND AGGREGATE STATES OF BURNING ALUMINUM DROPLETS IN PROPELLANT COMBUSTION

In this paper, the sizes and distributions of burning aluminum droplets during the combustion of aluminized composite propellants are showed. The influence of the sizes of both oxidizer and aluminum grains upon agglomeration is also discussed. The experimental results have shown that the aluminum grains obviously agglomerated in the coarse oxidizer propellants and that the fine aluminum powder is easier to agglomerate than the coarse one for the same size of coarse oxidizer propellants. The experimental results support the "pocket model" of the agglomeration of aluminum in composite propellants.The microphotodensity measurement of the streaks on the film has shown that there are three density distribution types: droplet type, mini-droplet type and liquid vapor transition type. Each of them represents an aggregate state of burning alumium droplets in the flame. Besides, the disappearance of the streaks classified as vapor phase type. The combustion efficiency of aluminum increases in the above sequence.