Fuel concentration in isothermal Diesel sprays through structured planar laser imaging measurements

Abstract The mixing of isothermal liquid sprays in engine-like conditions has been investigated by applying the structured planar laser imaging technique to remove multiple light scattering. The intensity of the illumination plane has been recovered by removing multiply scattered light and mapping the spray three-dimensionally via discrete tomography. Based on the extinction of light within the illumination plane, the number density has been extracted. Coupled with 2-D maps of droplet diameters obtained through LIF/Mie ratio, the number density allowed to calculate the fuel concentration in the sprays. The mixture fraction of DI Diesel sprays injected into an inert environment held at room temperature has been evaluated and compared to a 2-D model based on gas-jet theory. The experimental results showed good agreement with the predictions when a Gaussian radial distribution is assumed and the Schmidt number is correctly tuned. Differences in the radial distribution has been observed and related to incomplete momentum transfer between the liquid spray and the surrounding gases. For different testing conditions, while the influence of ambient density on mixing was expected, the effect of injection pressure has been found to provide additional information concerning the global mixing of liquid sprays.

[1]  Determination of the optical depth of a DI diesel spray , 2011 .

[2]  Dennis L. Siebers,et al.  Relationship Between Diesel Fuel Spray Vapor Penetration/Dispersion and Local Fuel Mixture Fraction , 2011 .

[3]  Y. Hardalupas,et al.  Spatial distribution of fluorescence intensity within large droplets and its dependence on dye concentration. , 2001, Applied optics.

[4]  Jesús Benajes,et al.  Planar Laser-Induced Fluorescence fuel concentration measurements in isothermal Diesel sprays. , 2002, Optics express.

[5]  J. M. Pastor,et al.  A 1D model for the description of mixing-controlled inert diesel sprays , 2008 .

[6]  Olawole Abiola Kuti,et al.  Experimental and analytical study on biodiesel and diesel spray characteristics under ultra-high injection pressure , 2010 .

[7]  R. Payri,et al.  Setting up a PDPA system for measurements in a Diesel spray , 2006 .

[8]  Franz Chmela,et al.  Influence of Cavitation in the Injection Nozzle on Combustion in Diesel Engines , 2010 .

[9]  M. Hartmann,et al.  Light scattering by small particles. Von H. C. VANDE HULST. New York: Dover Publications, Inc. 1981. Paperback, 470 S., 103 Abb. und 46 Tab., US $ 7.50 , 1984 .

[10]  R. Payri,et al.  Correction method for droplet sizing by laser-induced fluorescence in a controlled test situation , 2009 .

[11]  Suresh K. Aggarwal,et al.  Quantitative X-ray measurements of high-pressure fuel sprays from a production heavy duty diesel injector , 2009 .

[12]  T. Wilson,et al.  Method of obtaining optical sectioning by using structured light in a conventional microscope. , 1997, Optics letters.

[13]  M. Richter,et al.  Analysis of multiple scattering suppression using structured laser illumination planar imaging in scattering and fluorescing media. , 2011, Optics express.

[14]  Damon Honnery,et al.  Time resolved measurements of the initial stages of fuel spray penetration , 2009 .

[15]  L. Pickett,et al.  ANALYSIS OF MIXING PROCESSES IN LIQUID AND VAPORIZED DIESEL SPRAYS THROUGH LIF AND RAYLEIGH SCATTERING MEASUREMENTS , 2011 .

[16]  Su Han Park,et al.  Experimental and numerical analysis of spray-atomization characteristics of biodiesel fuel in various fuel and ambient temperatures conditions , 2009 .

[17]  Sibendu Som,et al.  Effect of nozzle orifice geometry on spray, combustion, and emission characteristics under diesel engine conditions , 2011 .

[18]  G. Herman,et al.  Discrete tomography : foundations, algorithms, and applications , 1999 .

[19]  M. Richter,et al.  High-speed structured planar laser illumination for contrast improvement of two-phase flow images. , 2008, Optics letters.

[20]  Su Han Park,et al.  Effects of Bioethanol-Blended Diesel Fuel on Combustion and Emission Reduction Characteristics in a Direct-Injection Diesel Engine with Exhaust Gas Recirculation (EGR) , 2010 .

[21]  M. Musculus.  Entrainment waves in decelerating transient turbulent jets , 2009, Journal of Fluid Mechanics.

[22]  H. V. Hulst.  Light Scattering by Small Particles , 1957 .

[23]  José M. Desantes,et al.  Evaporative diesel spray modeling , 2007 .

[24]  J. Naber,et al.  Effects of Gas Density and Vaporization on Penetration and Dispersion of Diesel Sprays , 1996 .

[25]  Mark Linne,et al.  Single-shot, two-dimensional ballistic imaging through scattering media. , 2004, Applied optics.

[26]  Christopher F. Powell,et al.  The Effects of Diesel Injector Needle Motion on Spray Structure , 2009 .

[27]  Elias Kristensson,et al.  Accounting for multiple scattering, signal attenuation and laser extinction using Structured Laser Illumination Planar Imaging , 2010 .

[28]  Sungwook Park,et al.  An experimental and numerical study on fuel atomization characteristics of high-pressure diesel injection sprays ☆ , 2002 .

[29]  Bernardo Tormos,et al.  Spray droplet velocity characterization for convergent nozzles with three different diameters , 2008 .

[30]  Raul Payri,et al.  A contribution to the understanding of isothermal diesel spray dynamics , 2007 .

[31]  J. M. Pastor,et al.  CorrigendumCorrigendum to “A 1D model for the description of mixing-controlled inert diesel sprays” [Fuel 87 (13–14) (2008) 2871–2885] , 2009 .

[32]  Tobias Breuninger,et al.  Lateral modulation boosts image quality in single plane illumination fluorescence microscopy. , 2007, Optics letters.

[33]  D. Potz,et al.  Diesel Nozzle — The Determining Interface Between Injection System And Combustion Chamber , 2002 .