Location of Repository

Optical measurement of nitric oxide and hydroxyl radicals distributions in combusting diesel sprays

By R. Demory

Abstract

The development and combusting behaviour of a diesel spray were investigated to provide a deeper understanding of the formation of nitric oxide (NO) in diesel engines. To characterise the spray, the nozzle flow was measured by the rate tube technique. The sensitivity of the flow to injection pressure was shown to follow the theoretical behaviour. Penetrations of the liquid spray were measured by means of high speed video imaging. The innovative measurements of the liquid penetration during the combustion allowed combustion phases and liquid jet lengths to be associated. Hydroxyl (OH) radicals were acquired by planar laser-induced fluorescence (PLIF). Combined with high speed videos of the flame natural luminosity, they were used to identify precisely the evolution of combustion in time and space. The measured OH distributions compared favourably with results from simulations using the KIVA code. The OH radicals were shown to be present mainly in the mixing controlled phase, distributed in a thin layer around the vapour fuel in the jet, within the diffusion flame location. OH radicals could be seen as early as 0.4 ms before the pre-mixed heat-release spike and until the end of apparent heat release. In the conditions studied, the diffusion flame, therefore, spanned most of the combustion process, starting very soon after autoignition. Finally distributions of NO were acquired by LIF and compared with the evolution of combustion. NO was found to appear 0.5 to 1 ms after the development of the diffusion flame, on the lean side of the flame front, outside the region with a high density of OH radicals but also later on, downstream the spray, on the outskirts of the zone with high soot density. The formation rate of NO was found almost constant during the mixing controlled combustion, with a small increase at the end of injection, when the flame collapsed on the fuel spray. The observed increase was linked to a rapid cooling of the flame plume and the associated freezing of the thermal-NO mechanism. Varying injection pressures did not significantly affect the overall formation rate although peak NO densities were seen to gradually move downstream the flame plume with increased injection pressure. NO formation increased with the in-cylinder pressure in accordance with a higher density of air and higher local temperatures

Topics: H330 Automotive Engineering
Year: 2007
OAI identifier: oai:eprints.brighton.ac.uk:3030

Suggested articles

Preview

Citations

  1. (1992). 2D SingleShot Imaging of OH Radicals Using Tunable Excimer Lasers.
  2. (1980). A Gas Sampling Study on the Formation Processes of Soot and NO in a DI Diesel Engine.
  3. (1995). A Laser-Induced Fluorescence scheme for Imaging Nitric Oxide in Engines.
  4. (2000). A New High-Pressure Diesel Spray Research Facility.
  5. (1990). A New Look at Oxygen Enrichment: 1) The Diesel Engine.
  6. (1995). A Rapid Compression Machine Investigation of Oxidation and AutoIgnition of n-Heptane: Measurements and Modeling. Combustion and Flame,
  7. (1992). A review of NOx Formation under Gas-Turbine Combustion.
  8. (1996). A study of mixture formation in a lean burn research engine using laser fluorescence imaging.
  9. (2003). A versatile modeling tool for nitric oxide LIF spectra.
  10. (2005). Advanced Diesel Combustion Strategies for Ultra-Low Emissions. School of Engineering.
  11. (1978). An Experimental Study of Diesel Engine Cylinder-Averaged Histories.
  12. (2002). Applied Combustion Diagnostics,
  13. (2003). Carbon dioxide UV laser-induced fluorescence in high-pressure flames.
  14. (1984). Chapter 6: Survey of Rate Constants in the N/H/O System. IN
  15. (2005). Charaterization of combustion and NO formation in a spray-guided gasoline direct-injection engine using chemiluminescence imaging, NO-PLIF, and fast NO exhaust gas analysis.
  16. (1998). Chemiluminescence Imaging of Autoignition in a DI Diesel Engine.
  17. (1995). Collisional Broadening of Spectral Lines in the A-X(0,0) System of NO by N2,Ar, and He at Elevated Pressures Measured by Laser-Induced Fluorescence.
  18. (1994). Collisional Quenching Corrections for Laser-Induced Fluorescence Measurements of NO .
  19. (2002). Combustion Processes in a Diesel Engine.
  20. (1984). Combustion Research with Lasers,
  21. (1998). Computational and Experimental Study of Soot Formation in a Coflow, Laminar Ethylene Diffusion Flame. Twenty Seventh Symposium (International) on Combustion. The Combustion Institute.
  22. (1997). Conceptual model of DI diesel combustion based on laser-sheet imaging. SAE paper no.
  23. (1998). Control of Oxides of Nitrogen from Diesel Engines Using Diluents While Minimising the Impact on Particulate Pollutants.
  24. (1994). Cylinder-Averaged Histories of Nitric Oxide in a D.I. Diesel with Simulated Turbocharging.
  25. (2006). Development of a calibrated technique for insitu investigation of air–fuel mixing in engines.
  26. (1992). DI diesel engine combustion visualised by combined laser techniques. 24th international symposium on combustion. The combustion institute.
  27. (1999). Diesel Combustion: An Integrated View Combining Laser Diagnostics, Chemical Kinetics, And Empirical Validation. SAE paper no.
  28. (2005). Diesel FuelInjection System -
  29. (2002). Effects of Oxygenated Compounds on Combustion and Soot Evolution in a D.I. Diesel Engine: Brodband Luminosity Imaging.
  30. (2004). Etude bibliographique de la mise en oeuvre de la fluorescence induite par laser pour l'imagerie du monoxyde d'azote dans des conditions moteur.,
  31. (1970). Experimental and Theoretical Study of Nitric Oxide Formation in Internal Combustion Engines.
  32. (1990). Fluorescence imaging inside an internal combustion engine using tunable excimer lasers.
  33. (2005). Fluorescence induite par laser du monoxyde d'azote dans un moteur a allumage commande en vue de l'etude de l'influence du melange gaz frais - gaz residuels sur la dispersion cyclique. Universite de Rouen.
  34. (1971). Formation of Nitric-Oxide in Premixed-Hydrocarbon Flames.
  35. (2003). Fuel effects on soot processes of fuel jets at DI diesel conditions.
  36. (2005). Fundamental Investigation of NOx Formation
  37. (2000). Fundamental of acoustics,
  38. (1994). Fundamentals of Molecular Spectroscopy,
  39. (1998). Handbook of Air Pollution from Internal Combustion Engines -Pollutant Formation and Control,
  40. (2003). Health effects of diesel exhaust.
  41. (1988). High-Sensitivity Detection of NO in a Flame Using a Tunable ArF Laser.
  42. (1998). Imaging and Post-Processing of Laser-Induced Fluorescence NO in a Diesel Engine.
  43. (1999). In-Cylinder measurements of NO formation in a Diesel Engine.
  44. (1994). Inelastic Scattering Laser Diagnostics; Cars, Plannar LIF and Plannar
  45. (1993). Instrumentation for Flows with Combustion,
  46. (2001). Internal Combustion Engines -Applied Thermosciences,
  47. (1988). Internal Combustion Engines Fundamentals,
  48. (1999). Introduction to Internal Combustion Engines,
  49. (1975). Kinetics of Pollutant Formation and Destruction in Combustion.
  50. (2000). Lambdachrome Laser Dyes. Lambda Physik AG.
  51. (2000). Laser Diagnostic Analysis of NO Formation in a Direct Injection Diesel Engine with Pump-Line-Nozzle and Common Rail Injection Systems.
  52. (1996). Laser Diagnostics for Combustion Temperature and Species,
  53. (1998). Laser Diagnostics of Nitric Oxide inside a Two-Stroke DI Diesel Engine. selected papers from the 9th International Symposium,
  54. (1990). Laser in situ monitoring of combustion processes.
  55. (1997). Laser Induced Fluorescence Spectroscopy in Flames.
  56. (1994). Laser Techniques for the Quantitative Detection of Reactive Intermediates in Combustion Systems.
  57. (2005). Laser-Based Diagnostics in a Diesel Flame: Flame Structure. Engineering Research in Action.
  58. (1998). Laser-based diagnostics on NO in a diesel engine.
  59. (1997). Laser-Induced Fluorescence Detection of Nitric Oxide in High-Pressure Flames with A-X(0,2) excitation.
  60. (2007). Laser-Induced Fluorescence Investigation of Nitric Oxide Formation in a Diesel Rapid Compression Machine. SAE Powertrain & Fluids.
  61. (1995). Laser-Induced Fluorescence Measurements of NO and OH Mole Fraction in Fuel-Lean, High-Pressure (1-10 atm) Methane Flames: Fluorescence Modeling and Experimental Validation.
  62. (1988). Laser-Induced Fluorescence with Tunable Excimer Lasers as a Possible Method for Instantaneous Temperature Field Measurements at High Pressures.
  63. (1993). Laser-Induced-Fluoresence Imaging of NO in an nHeptane- and Diesel-Fuel-Driven Diesel Engine.
  64. (1999). Laser-Spectroscopic Investigation of OHRadical Concentrations in the Exhaust Plane of Jet Engines.
  65. (2000). LaserInduced Fluorescence Imaging of NO in a DI Diesel Engine using KrF Excimer Radiation. Towards Clean Diesel Engines,
  66. (2001). LIF Diagnostics of NO Molecules in Atmospheric Pressure DC Streamer Coronas Used for NOx Abatement. Arbeitsgemeinshaft PlasmaPhysik (APP) Spring Meeting "Diagnostics of Non-Equilibrium High Pressure Plasmas".
  67. (2000). LIF imaging and 2D temperature mapping in a model combustor at elevated pressure.
  68. (2007). LIF Measurements of Nitric Oxide in a Combusting Diesel Spray. Combustion and Flame, under review.
  69. (1999). LIFBASE, Database and spectral simulation for diatomic molecules (v 1.6).
  70. (2001). Measurements and simulations of incylinder UV-absorption in spark ignition and Diesel engines.
  71. (2006). Measuring and processing in-cylinder distributions of NO and OH obtained by laser-induced fluorescence in a diesel rapid compression machine. Applied Laser Techniques to Fluid Mechanics.
  72. (1989). Mechanism and modeling of nitrogen chemistry in combustion.
  73. (2004). Multiwavelength ultraviolet absorption spectroscopy of NO and OH radical concentration applied to a high-swirl diesel-like system. Experimental thermal and Fluid
  74. (1999). Nitric oxide in a diesel engine: laser-based detection and interpretation.
  75. (1997). NO measurement in Diesel Spray Flame using Laser Induced Fluorescence.
  76. (1999). NO vibrational spectra (Luque and Crosley,
  77. (2006). OH and NO Distributions in Combusting Diesel Sprays. Engineering in Action.
  78. (1996). OH Radical Imaging in a DI Diesel Engine and the Structure of the Early Diffusion Flame.
  79. (2001). Oxygenates for Advanced Petroleum-Based Diesel Fuels: Part1. Screening and Selection Methodology for the Oxygenates.
  80. (2001). Oxygenates Screening for Advanced Petroleum-Based Diesel Fuels: Part 2. The Effect of Oxygenate Blending Compounds on Exhaust Emissions.
  81. (1992). PDF modeling and analysis of thermal NO formation in turbulent nonpremixed hydrogen-air jet flames.
  82. (1974). Photographic and Performance Studies of Diesel Combustion with a Rapid Compression Machine.
  83. (1990). Planar Laser-Fluorescence Imaging of Combustion Gases.
  84. (1995). Planar Laser-Induced Fluorescence Imaging Measurements of OH and Hydrocarbon Fuel Fragments in High-Pressure Spray-Flame Combustion.
  85. (2002). Planar LaserInduced Fluorescence Fuel Concentration Measurements in Isothermal Diesel Sprays.
  86. (1993). PLIF Imaging of Fuel Fraction in Practical Devices and LII Imaging of Soot.
  87. (1998). PLIF Imaging of NO Formation in a DI Diesel Engine.
  88. (1997). Predictions of Soot Dynamics in Opposed Jet Diffusion Flames. IN
  89. (1988). Quantitative CARS Spectroscopy. IN
  90. (2006). Quantitative Laser-Induced Fluorescence Measurements of Nitric-Oxide in a Heavy-Duty Diesel Engine.
  91. (2000). Quantitative measurements of nitric oxide in high-pressure (2-5 atm), swirl-stabilized spray flames via laser-induced fluorescence.
  92. (2002). Quantitative NO-LIF imaging in high-pressure flames.
  93. (1995). Quantitative Two-Dimensional Measurements of Nitric Oxide and Temperature Distributions in a Transparent Square Piston SI Engine.
  94. (1998). Radical Emission and Fluorescence Measurements in Pulsed Flame Jet.
  95. (1996). Raman-LIF Measurements of Temperature, Major Species, OH, and NO in a Methane-Air Busen Flame. Combustion and Flame,
  96. (1996). Simultaneous 2-D Imaging of OH-Radicals and Soot in a Diesel Flame by Laser Sheet Techniques.
  97. (1989). Simultaneous Measurement of Raman Scattering and Laser-Induced OH Fluorescence in Nonpremixed Turbulent Jet Flames.
  98. (1996). Simultaneous Two-Dimensional Visualization of Soot and OH in Flames Using Laser-Induced Fluorescence.
  99. (2005). Soot Formation in Laminar Diffusion Flames. Combustion and Flame,
  100. (1988). Spectrochemical analysis,
  101. (1987). Superequilibrium and Thermal Nitric Oxide Formation in Turbulent Diffusion Flames.
  102. (1998). Suppresion of Reaction During Rapid Compression and Its Effect on Ignition Delay. Combustion and Flame,
  103. (2004). Technology Development to Meet the Future Demand for Passenger Car Diesel Engines with Lower Emissions and Higher Performance.
  104. (1992). Temperature dependence of collision broadening and shift in the NO A <-- X (0, 0) band in the presence of argon and nitrogen.
  105. (2001). Temporally resolved single-cycle measurements of fuel- and OH- distributions in a spark ignition engine using high speed laser spectroscopy.
  106. (1977). The autoignition of hydrocarbon fuels at high temperatures and pressures--Fitting of a mathematical model.
  107. (1996). The Effect of Exhaust Gas Recirculation on Combustion and NOx Emissions in a High-Speed Direct-Injection Diesel Engine.
  108. (2000). The Evolution of Photochemical Smog in the Metropolitan Area of Santiago de Chile.
  109. (2001). The influence of injector parameter on the formation and breakup of a Diesel spray.
  110. (1992). The Laser Guidebook,
  111. (1946). The Oxidation of Nitrogen in Combustion and Explosions.
  112. (2000). The P-1 Model for Thermal Radiation Transfer: Application to Numerical Modeling
  113. (1999). The Shell Autoignition Model: Applications to Gasoline and Diesel Fuels.
  114. (1993). the thermal NO mechanism is normally limited by the availability of oxygen atoms, whose concentration scales as
  115. (1962). The ultraviolet bands of
  116. (1994). Understanding Lasers, an Entry-Level Guide,
  117. (2004). Using carbon-14 isotope tracing to investigate molecular structure effects of the oxygenate dibutyl maleate on soot emissions from a DI diesel engine. Spring Fuels and Lubricants Conference and Exhibition.

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.