Burning Rates of Turbulent Gaseous and Aerosol Flames
Combustion of sprays is of technological importance, but its flame behavior is not fully understood. Furthermore, the multiplicity of dependent variables such as pressure, temperature, equivalence ratio, and droplet sizes complicates the study of spray combustion. Fundamental study on the influence of the presence of liquid droplets has revealed that laminar flames within aerosol mixtures more readily become unstable than for gaseous ones and this increases the practical burning rate. However, fundamental studies on turbulent flames of aerosol mixtures are limited particularly those under near mono-dispersed droplet conditions. In the present work, centrally ignited expanding flames at near atmospheric pressures are employed to quantify the burning rates in gaseous and aerosol flames. Iso-octane-air aerosols are generated by expansion of the gaseous pre-mixture to produce a homogeneously distributed suspension of fuel droplets. The effects of the presence of droplets and turbulence velocity in relation to the burning rates of the flame are also investigated.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1063364Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1278
 J. B. Greenberg, "Propagation and Extinction of an Unsteady Spherical Spray Flame Front," Combust. Theory Modelling, vol. 7, pp. 163-174, 2003.
 T. H. Lin and Y. Y. Sheu, "Theory of Laminar Flame Propagation in Near-Stoichiometric Dilute Sprays, Combustion and Flame," Combustion and Flame, pp. 333, 1991.
 G. D. Myers and A. H. Lefebvre, "Propagation in Heterogeneous Mixtures of Fuel Drops and Air," Combustion and Flame, vol. 66, pp. 193-210, 1986.
 G. A. Richards and A. H. Lefebvre, "Turbulent Flame Speeds of Hydrocarbon Fuel Droplets in Air," Combustion and Flame, vol. 78, pp. 299-307, 1989.
 D. R. Ballal and A. H. Lefebvre, "Flame Propagation in Heterogeneous Mixtures of Fuel Droplets, Fuel Vapor and Air," Proc. Combust. Inst., 1981.
 Y. Mizutani and A. Nakajima, "Combustion of Fuel Vapour-Drop-Air Systems: Part II, Spherical Flames in a Vessel," Combustion and Flame, vol. 21, pp. 351-357, 1973.
 Y. El-Banhawy and J. H. Whitelaw, "Experimental Study of the Interaction Between a Fuel Spray and Surrounding Combustion Air," Combustion and Flame, vol. 42, pp. 253-275, 1981.
 S. H. St├Ñrner, J. Gounder, and A. R. Masri, "Effects of Turbulence and Carrier Fluid on Simple, Turbulent Spray Jet Flames," Combustion and Flame, vol. 143, pp. 420-432, 2005.
 N. Marquez, Fundamental Studies of Aerosol Flames, PhD Thesis, School of Mechanical Engineering, University of Leeds, UK, 2003.
 D. Bradley, R. A. Hicks, M. Lawes, C. G. W. Sheppard, and R. Woolley, "The Measurement of Laminar Burning Velocities and Markstein Numbers of Iso-Octane-Air and Iso-Octane-n-Heptane-Air Mixtures at Elevated Temperatures and Pressures in an Explosion Bomb," Combustion and Flame, vol. 115, pp. 126-144, 1998.
 M. Lawes, Y. Lee, and N. Marquez, "Comparison of Iso-octane Burning Rates between Single-phase and Two-phase Combustion for Small Droplets," Combustion and Flame, vol. 144, pp. 513-525, 2006.
 C. T. R. Wilson, "Condensation of Water Vapour in the Presence of Dust-Free Air and Other Gases," Proc. of the Royal Society of London, 1897.
 M. Lawes, Effects of Turbulence on Combustion in Engines, PhD Thesis, School of Mechanical Engineering, University of Leeds, 1987.
 K. Nakabe, Y. Mizutani, F. Akamatsu, M. Fuchihata, and S. H. ElEmam, "Spark-Ignited Spherical Flames Propagating in a Suspended Droplet Cloud," 5th International Conference on Liquid Atomization and Spray Systems (ICLASS-91), 1991.
 S. Hayashi and S. Kumagai, "Flame Propagation in Fuel Droplet-Vapor- Air Mixtures," Proc. Combustion Institute, 1974.
 S. Hayashi, S. Kumagai, and T. Sakai, "Propagation Velocity and Structure of Flames in Droplet-Vapor-Air Mixtures," Combustion Science & Technology, vol. 15, pp. 169-177, 1976.
 W. D. Bachalo, A. B. Rosa, and S. V. Sankar, Diagnostic for Fuel Spray Characterization, in Combustion Measurements, N. Chigier, Ed., New York, Hemisphere, 1991.
 S. A. Sulaiman, M. Lawes, S. Hassan, and Z. A. Abdulkarim, "High- Speed Schlieren Imaging of Spherically Propagating Laminar Flames of Iso-Octane-Air Aerosol Mixtures," 3rd World Engineering Congress, Penang, 2007.
 S. A. Sulaiman and M. Lawes, "High-Speed Schlieren Imaging and Post- Processing for Investigation of Flame Propagation within Droplet- Vapour-Air Fuel Mixtures," IEM Journal, vol. 69, pp. 53-60, 2008.
 S. A. Sulaiman, Burning Rates and Instabilities in the Combustion of Droplet and Vapour Mixtures, PhD Thesis, Department of Mechanical Engineering, University of Leeds, UK, 2006.
 Y. Ali, D. Bradley, M. Lawes, and E. M. J. Mushi, "Problems of the Measurement of Markstein Lengths with Explosion Flames," The Combustion Institute, Proceedings of the British and German Sections, Queen's College Cambridge, 1993.
 M. P. Ormsby, Turbulent Flame Development in a High-Pressure Combustion Vessel, School of Mechanical Engineering, University of Leeds, 2005.
 R. Maly, Spark Ignition: Its Physics and Effect on the Internal Combustion Engine, in Fuel economy in Road Vehicles Powered by Spark Ignition Engines, J. C. Hilliard and G. S. Springer, Eds, New York, Plenum Press, 1984.