M.Sc Thesis

M.Sc StudentWeinberg Noam
SubjectAn Investigation of Certain Aspects of the Behavior
of Spray Flames
DepartmentDepartment of Mechanical Engineering
Supervisor PROFESSOR EMERITUS Jerrold Greenberg
Full Thesis text - in Hebrew Full thesis text - Hebrew Version


This research considers the stability of a double-spray premixed flame formed when both fuel and oxidizer are initially present in the form of sprays of evaporating liquid droplets. Double-spray flames are quite commonly found in space applications. Because of the inherent complexity that characterizes that analytic solution of combustion problems, especially those of multi-phase combustion processes, some simplifying assumptions were made. We restricted our analysis to fuel-rich laminar premixed double-spray flames, and assume a single-step global chemical reaction mechanism. A mathematical diffusive-thermal model was adopted and solved with an asymptotic approach. In the first part of the research, the double-spray flame was considered to be planar and to propagate in a steady-state mode. Some characteristic parameters of the flame, such as its temperature and velocity, were then found and their dependence on the spray related parameters was investigated. The second part of the research was devoted to a linear stability analysis of the double-spray flame - here done for the first time ever. The results of this analysis, showed that the presence of fuel and/or oxidizer droplets in the fresh unburned fuel-oxidizer mixture has a significant influence on the stability of the double-spray flame, are in good qualitative agreement with both empirical and theoretical studies of the related single fuel-spray flames that have been carried out in the recent years.