NEPE推进剂燃烧表面铝团聚物动态行为研究

Dynamic Behavior Study of Aluminum Aggregates on NEPE Propellant Combustion Surface

关键词:  NEPE推进剂  铝颗粒  团聚  高速摄像  燃烧理论

Key words:  NEPE propellant  Aluminum particles  Agglomeration  High-speed photography  Combustion theory

摘要:

针对NEPE推进剂燃烧表面铝团聚物的动态行为，在1，2，3MPa的N₂环境中，对NEPE推进剂中铝团聚物在燃烧表面和脱离燃面后的动态燃烧过程进行了研究，提出了燃面与铝颗粒联合运动的简化理论模型。结果表明，铝颗粒的团聚分为堆积、聚集和团聚三个过程，铝团聚物在燃烧表面以及脱离燃面后均可能发生二次团聚，铝团聚物的二次团聚过程通常会形成大尺寸的铝团聚物。通过燃面与铝颗粒协同运动的简化理论模型，认为铝团聚的团聚时间受到压强、铝颗粒的体积分数和半径的影响。同尺寸铝团聚物的团聚时间随着压强的增大而较小，且在高压环境中的影响程度降低，与理论模型一致。同时压强会影响铝团聚物脱离燃面后的随流运动速率，同一压强条件下，直径越小的初始团聚物随流运动速率越快，直径越大的初始团聚物随流运动速率越慢。

Abstract:

Aiming at the dynamic behavior of aluminum agglomerates on the burning surface of NEPE propellant， the dynamic combustion process of aluminum agglomerates at the surface and out of the burning surface of aluminum in the NEPE propellant was studied under 1， 2， 3MPa nitrogen environment， and a simplified theoretical model for the burning surface-particle motion was proposed. The results show that the agglomeration of aluminum particles can be divided into three processes： accumulation， aggregation and agglomeration. The secondary agglomeration of aluminum particles may occur on the propellant surface and out of the burning surface， which usually leads to the formation of large-size agglomerate. Based on the simplified theoretical model， it is believed that the agglomeration time of aluminum agglomeration is affected by the pressure， the volume fraction， and radius of the aluminum particles. The same size aluminum agglomeration time decreases with the increase of pressure， and the degree of influence in the high-pressure environment decreases， which is consistent with the simplified theoretical model. At the same time， the pressure will affect the flow velocity of the aluminum agglomerates after they leave the combustion surface. Under the same pressure condition， the initial agglomerates with a smaller diameter move faster with the flow， and the initial agglomerates with a larger diameter move more slowly with the flow.