Numerical study on combustion efficiency of aluminum particles in solid rocket motor

作     者：Junlong WANG Ningfei WANG Xiangrui ZOU Wei DONG Yintao ZHOU Dingjiang XIE Baolu SHI Junlong WANG;Ningfei WANG;Xiangrui ZOU;Wei DONG;Yintao ZHOU;Dingjiang XIE;Baolu SHI

作者机构：School of Aerospace EngineeringBeijing Institute of TechnologyBeijing 100081China China Academy of Launch Vehicle TechnologyBeijing 100076China 

出 版 物：《Chinese Journal of Aeronautics》 (中国航空学报（英文版）)

年 卷 期：2023年第36卷第5期

页      面：66-77页

核心收录：

学科分类：080703[工学-动力机械及工程] 082502[工学-航空宇航推进理论与工程] 08[工学] 0807[工学-动力工程及工程热物理] 0825[工学-航空宇航科学与技术] 

基　　金：supported by the National Natural Science Foundation of China(Nos.11972087 and U20B2018) the Domain Foundation of Equipment Advance Research of 13th Five-year Plan,China(No.61407200201) 

主　　题：Aluminum Combustion efficiency Eulerian-Lagrangian Particle size Solid rocket motor 

摘      要：The combustion of aluminum particles in solid rocket motor plays an important role in energy release of propellants. However, due to the limited residence time, aluminum particles may not be burned completely, thus hindering the improvement of specific impulse. This study aims to explore the characteristics of aluminum combustion efficiency and its influencing factors by experiments and numerical simulations, providing a guideline for engine performance improvement. As an input of simulation, the initial agglomerate size was measured by a high pressure system. Meanwhile, the size distribution of the particles in plume was measured by ground firing test to validate the numerical model. Then, a two-phase flow model coupling combustion of micro aluminum particle was developed, by which the detailed effects of particle size, detaching position and nozzle convergent section structure on aluminum combustion efficiency were explored. The results suggest that the average combustion temperature in the chamber drops with increasing initial particle size,while the maximum temperature increases slightly. In the tested motors, the aluminum particle burns completely as its diameter is smaller than 50 μm, and beyond 50 μm the combustion efficiency decreases obviously with the increase of initial size. As the diameter approaches to 75 μm, the combustion efficiency becomes more sensitive to particle size. The combustion efficiency of aluminum particle escaping from end-burning surfaces is significantly higher than that from internal burning surface, where the particle combustion efficiency decreases during approaching the convergent section. Furthermore, the combustion efficiency decreases slightly with increasing nozzle convergent section angle. And theoretically it is feasible to improve combustion efficiency of aluminum particles by designing the convergent profile of nozzle.