Investigation of Organic-Gellant Droplets Evaporation Characteristics in the Static Environment

Paper number

IAC-11,C4,1,14,x10929

Author

Mr. Zejun Liu, College of Aerospace and Materials Engineering, National University of Defense Technology, China

Coauthor

Dr. Jianjun Wu, National University of Defense Technology, China

Coauthor

Dr. Zhen He, College of Aerospace and Materials Engineering, National University of Defense Technology, China

Year

2011

Abstract

Gelled propellants combine the advantages of solid propellants like storage behavior and safety aspects with that of liquid propellants like high performance, wide range thrust control and re-ignitability, which makes them attractive for many applications. However, before gels can be widely used, their combustion processes must be well understood, understanding the evaporation process of single droplets of gel fuels is the first basic step to predict their behavior in the future combustion chambers. 
This paper, base on isothermal droplet evaporation model and taking into account the dependency of the physical properties of gas and liquid on thermal environment and ambient pressure, steady evaporation model and unsteady evaporation model, as well unsteady species diffusion model inside droplets have been numerically/analytically solved，in order to investigate process of organic-gellant droplets evaporation and phase separation under the different ambient temperature and pressure. 
The results indicate that evaporation has occurred at droplet transient heating stage. The evaporation rate and Stefan flow of the liquid fuel from the droplet surface depend on environment temperature. The evaporating rate increases as ambient temperature increases; the higher ambient pressure benefits steady evaporation, on the contrary, results in a reduced unsteady evaporating rate (due to the time required for droplet transient heating and steady evaporation temperature increasing).
The evaporating rate strongly affects the time of phase separation (the time required for the fuel concentration at the surface to diminish to less than 1\%) and the thickness of the gellant layer.

Abstract document

IAC-11,C4,1,14,x10929.brief.pdf

Manuscript document

IAC-11,C4,1,14,x10929.pdf (🔒 authorized access only).

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