关键词: 凝胶燃料;液滴燃烧;相分离;质量输运;热量输运

Abstract: Understanding the combustion mechanisms of single droplet is the first stage to predict the burning characteristics of gelled fuel in the combustion chamber. Therefore, to investigate the special combustion mechanism of gelled fuel droplets, a new mathematical model was firstly developed to describe their phase separation process in the consideration of the inner gradient change of temperature and concentration. Then the model was used to investigate the phase separation characteristics of the gelled fuel droplets in their evaporation and combustion process. Results show that shrinkage of the radius obeys the d²-law and it agrees well with experimental measurements at the phase separation stage. Then, after the droplet ignited, the flame will expand from the initial location to the peripheries of droplets with temperature of the flame increasing and gradually tending to be stable. Furthermore, in the prophase of the phase separation, the mass is easier than the heat to transport inside the droplets, especially in the nearby surface region. However, the above process is on the contrary in the anaphase of the phase separation, which leads to the higher temperature gradient in the prophase of the phase separation, and the higher base fuel mass concentration gradient in the anaphase of the phase separation. 

Key words: Gelled fuel; Droplet combustion; Phase separation; Mass transport; Heat transport