Effect of the mixing fields on the stability and structure of turbulent partially premixed flames in a concentric flow conical nozzle burner
AuthorsMansour, Mohy S.
Elbaz, Ayman M.
Roberts, William L.
Senosy, Mohamed S.
Zayed, Mohamed F.
Masri, Assaad R.
KAUST DepartmentClean Combustion Research Center
MetadataShow full item record
AbstractThe mixing field is known to be one of the key parameters that affect the stability and structure of partially premixed flames. Data in these flames are now available covering the effects of turbulence, combustion system geometry, level of partially premixing and fuel type. However, quantitative analyses of the flame structure based on the mixing field are not yet available. The aim of this work is to present a comprehensive study of the effects of the mixing fields on the structure and stability of partially premixed methane flames. The mixing field in a concentric flow conical nozzle (CFCN) burner with well-controlled mechanism of the mixing is investigated using Rayleigh scattering technique. The flame stability, structure and flow field of some selected cases are presented using LIF of OH and PIV. The experimental data of the mixing field cover wide ranges of Reynolds number, equivalence ratio and mixing length. The data show that the mixing field is significantly affected by the mixing length and the ratio of the air-to-fuel velocities. The Reynolds number has a minimum effect on the mixing field in high turbulent flow regime and the stability is significantly affected by the turbulence level. The temporal fluctuations of the range of mixture fraction within the mixing field correlate with the flame stability. The highest point of stability occurs at recess distances where fluid mixtures near the jet exit plane are mostly within the flammability limits. This paper provides some correlations between the stability range in mixture fraction space and the turbulence level for different equivalence ratios.
CitationMansour MS, Elbaz AM, Roberts WL, Senosy MS, Zayed MF, et al. (2017) Effect of the mixing fields on the stability and structure of turbulent partially premixed flames in a concentric flow conical nozzle burner. Combustion and Flame 175: 180–200. Available: http://dx.doi.org/10.1016/j.combustflame.2016.08.032.
SponsorsProfessor Masnour was supported by a research grant from the American University in Cairo to conduct the measurements at Sydney University. Professor Masri and Dr Juddoo were supported by the Australian Research Council. The work conduct in KAUST was supported by Center Competitive Research funding.
JournalCombustion and Flame