Abstract In order to gain insight into aluminum agglomeration behaviors and agglomeration processes, the aluminized fuel-rich propellants in solid fuel ramjet are investigated by using sampling method followed by scanning electron microscopy and laser scattering experimental technique on the small-scale combustion experimental system and connected-pipe experimental system. It is observed that the aluminum particles would break away from the burning surface after agglomeration, and interpocket agglomeration occurred. Under different ambient pressures, the microstructure of the combustion products and the aggregation behavior of aluminum particles are further analyzed. Based on the classical pocket theory and particle size analysis experiments, a new agglomeration size prediction model is established. It can be used to predict the agglomeration size on the burning surface. Compared with the empirical model and the typical pocket model, this model is in good agreement with the experimental results. A connected-pipe experimental system for solid fuel ramjet is established. The effects of inlet air temperatures on the combustion performance of ramjet, the microstructure and agglomeration size are studied. With the increase of inlet air temperature, the agglomeration size decreases, the pressure, temperature and thrust in the combustion chamber increase, which makes the propellant burn more fully. The characteristic velocity, specific impulse and combustion efficiency of the solid fuel ramjet increase.

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固体燃料冲压发动机含铝富燃料推进剂团聚实验及模型研究

摘要 为深入了解铝的团聚行为和团聚过程，在小型燃烧实验系统上，采用取样、扫描电镜和激光散射实验技术，对固体燃料冲压发动机中的含铝富燃料推进剂进行了研究。 -管道实验系统。观察到铝颗粒在团聚后会从燃烧表面脱离，并发生孔间团聚。进一步分析了不同环境压力下燃烧产物的微观结构和铝颗粒的聚集行为。基于经典口袋理论和粒度分析实验，建立了新的团聚尺寸预测模型。它可用于预测燃烧表面的团聚尺寸。与经验模型和典型口袋模型相比，该模型与实验结果吻合较好。建立了固体燃料冲压发动机连管实验系统。研究了进气温度对冲压发动机燃烧性能、微观结构和团聚尺寸的影响。随着进气温度的升高，团块尺寸减小，燃烧室内的压力、温度和推力增加，使推进剂燃烧更充分。固体燃料冲压发动机的特征速度、比冲量和燃烧效率提高。该模型与实验结果吻合良好。建立了固体燃料冲压发动机连管实验系统。研究了进气温度对冲压发动机燃烧性能、微观结构和团聚尺寸的影响。随着进气温度的升高，团块尺寸减小，燃烧室内的压力、温度和推力增加，使推进剂燃烧更充分。固体燃料冲压发动机的特征速度、比冲量和燃烧效率提高。该模型与实验结果吻合良好。建立了固体燃料冲压发动机连管实验系统。研究了进气温度对冲压发动机燃烧性能、微观结构和团聚尺寸的影响。随着进气温度的升高，团块尺寸减小，燃烧室内的压力、温度和推力增加，使推进剂燃烧更充分。固体燃料冲压发动机的特征速度、比冲量和燃烧效率提高。团块尺寸减小，燃烧室压力、温度和推力增加，推进剂燃烧更充分。固体燃料冲压发动机的特征速度、比冲量和燃烧效率提高。团块尺寸减小，燃烧室压力、温度和推力增加，推进剂燃烧更充分。固体燃料冲压发动机的特征速度、比冲量和燃烧效率提高。