Droplet characteristics and local equivalence ratio of reacting mixture in spray counterflow flames
File(s)PrePub_Accepted_14.pdf (1.38 MB)
Accepted version
Author(s)
Orain, M
Hardalupas, Y
Type
Journal Article
Abstract
Spray combustion was studied by injecting monodisperse 125 or 200 μm ethanol droplets in a premixed natural gas fuel flame flowing against an opposed heated air jet. Phase Doppler anemometry and chemiluminescence measurements allowed to characterise both droplet parameters and the local reacting mixture. Both types of droplets crossed the flow stagnation plane and entered the opposite jet. However, 125 μm droplets reversed their motion and oscillated around the stagnation plane, leading to increased droplet residence time in hot regions. The fuel vapour released by droplets close to the stagnation plane, mixed with the surrounding air and led to the ignition of a second fuel vapour flame below the natural gas flame. For 125 μm droplets, mean local equivalence ratio of the fuel vapour flame was about 0.8, suggesting lean-premixed combustion; whereas 200 μm droplets led to stoichiometric combustion. “Group Combustion” number was estimated from measurements and suggested that 125 μm and 200 μm droplets burned in different “Group Combustion” regimes.
Date Issued
2014-05-28
Date Acceptance
2014-05-16
Citation
Experimental Thermal and Fluid Science, 2014, 57, pp.261-274
ISSN
0894-1777
Publisher
Elsevier
Start Page
261
End Page
274
Journal / Book Title
Experimental Thermal and Fluid Science
Volume
57
Copyright Statement
© 2014, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Subjects
Science & Technology
Physical Sciences
Technology
Thermodynamics
Engineering, Mechanical
Physics, Fluids & Plasmas
Engineering
Physics
ENGINEERING, MECHANICAL
PHYSICS, FLUIDS & PLASMAS
THERMODYNAMICS
Spray counterflow flames
Droplet combustion
Local equivalence ratio
Droplet size
Chemiluminescence
DIFFUSION FLAMES
LAMINAR COUNTERFLOW
CHEMILUMINESCENT EMISSION
HEAT RELEASE
CH-ASTERISK
OH-ASTERISK
LIQUID FUEL
COMBUSTION
EXTINCTION
CHEMISTRY
Publication Status
Published