Nano organic carbon and soot in turbulent non-premixed ethylene flames

2007-01-01
D'Anna, Andrea
Commodo, Mario
Violl, Santo
Allouis, Christophe Gerard
Kent, John
Spectral optical techniques are combined to characterise the distribution of large-molecule soot precursors, nanoparticles of organic carbon, and soot in two turbulent non-premixed ethylene flames with differing residence times. Laser-induced fluorescence, laser-induced incandescence and light scattering are used to define distributions across the particle size distribution. From the scattering and laser-induced emission measurements it appears that two classes of particles are formed. The first ones are preferentially formed in the fuel-rich region of the flame closer to the nozzle, have sizes of the order of few nanometers but are not fully solid particles, because the constituent molecules still maintain their individual identity exhibiting strong broadband fluorescence in the UV. The second class of particles constituted by solid particles, with sizes of the order of tens of nanometers are able to absorb a sufficient number of photons to be heated to incandescent temperatures. These larger particles are formed at larger residence times in the flame since they are the result of slow growth processes such as coagulation or carbonization. The flames are also modeled in order to produce mixture fraction maps. A new discovery is that nanoparticles of organic carbon concentration, unlike soot, does correlate well with mixture fraction, independent of position in the flame. This is likely to be a significant benefit to future modelling of soot inception processes in turbulent nonpremixed flames. (c) 2006 The Combustion Institute. Published by Elsevier Inc. All rights reserved.
PROCEEDINGS OF THE COMBUSTION INSTITUTE

Suggestions

Synergistic fire retardancy of colemanite, a natural hydrated calcium borate, in high-impact polystyrene containing brominated epoxy and antimony oxide
Kaynak, Cevdet (2011-05-01)
This study explores for the first time the synergistic fire retardant action of natural hydrated calcium borate, namely the mineral colemanite, which partially replaces antimony oxide in brominated flame retardant high-impact polystyrene compounds. Various antimony oxide to hydrated calcium borate ratios were employed keeping the brominated flame retardant additive at a constant loading level. With partial colemanite substitution for antimony oxide, lower heat release rate, total heat evolved and fire growt...
Nano-Sized Iron Precipitation in Ni-Al-Fe Alloys
Duman, Nagehan; Mehrabov, Amdulla; Akdeniz, Mahmut Vedat (2010-06-15)
Iron precipitation behavior has been investigated for different annealing treatments in Ni50Al50-xFex ternary alloys. The formation of ferromagnetic nano-sized α-Fe precipitates, as evidenced by transmission electron micrographs and magnetic measurements, provides enhancements in magnetic properties.
NANOSTRUCTURE OF SOOT COLLECTED FROM ETHANOL DROPLET FLAMES IN MICROGRAVITY
Park, Seul-Hyun; Choi, Mun Young; Yozgatlıgil, Ahmet (Informa UK Limited, 2009-01-01)
The nanostructure of soot particles collected from spherically symmetric ethanol droplet flames were analyzed using a high resolution transmission electron microscopy (HRTEM). Nanostructure properties, including fringe length and curvature of carbon lamellae, were measured for soot particles collected in various inert environments. The sampling experiments were performed in the reduced gravity environments produced in the NASA 2.2 sec Droptower at the Glenn Research Center in Cleveland, Ohio. Microgravity d...
Hydrothermal vents as a kinetically stable source of iron-sulphide-bearing nanoparticles to the ocean
Yücel, Mustafa; Chan, Clara S.; Luther, George W. (2011-06-01)
Hydrothermal vents emit sulphur and metals to the ocean(1). Particular attention has been paid to hydrothermal fluxes of iron(2-4), a limiting micronutrient of marine primary production(5). Vent-derived iron was previously thought to rapidly oxidize and precipitate around vents(6). However, organic matter can bind to and stabilize dissolved and particulate iron in hydrothermal plumes(7-9), facilitating its dispersion into the open ocean(10). Here, we report measurements of the chemical speciation of sulphid...
Epoxy-based composites and coatings: improvement of multifunctional properties
Çaldıklıoğlu, Almira; Bayram, Göknur; Department of Chemical Engineering (2019)
The purposes of this study are to improve mechanical properties, thermal stability, resistance to flammability, electrical conductivity and hydrophobicity of epoxy (E) by incorporation of expanded graphite (EG) and titanium dioxide (T) particles. In this study, sonication with the use of solvent method was primarily determined for the epoxy-based binary composite and coating preparation. By this method, the epoxy composites and coatings were produced by changing EG concentration as 0.05, 0.1, 0.25, 0.5, 0.7...
Citation Formats
A. D’Anna, M. Commodo, S. Violl, C. G. Allouis, and J. Kent, “Nano organic carbon and soot in turbulent non-premixed ethylene flames,” PROCEEDINGS OF THE COMBUSTION INSTITUTE, pp. 621–629, 2007, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/89886.