Combustion process of JP-8 and fossil Diesel fuel in a heavy duty diesel engine using two-color thermometry

Abstract An experimental study was performed to analyze the combustion processes of JP-8 and fossil Diesel fuel in an optically-accessible single-cylinder heavy-duty diesel engine equipped with a high pressure common-rail injection system. In terms of emission, JP-8 emitted less smoke with more HC and NOx. Direct imaging and two-color thermometry were applied to verify the emission trend for both fuels. The combustion process was characterized by means of image analysis focusing on the luminosity intensity and its spatial distribution (flame spatial fluctuation (FSF) and flame non-homogeneity (FNH)). The results from the two-color thermometry were analyzed by the flame temperature and KL factor distribution. From the combustion process analysis of the direct imaging, it was verified that JP-8 had a longer ignition delay compared to fossil Diesel fuel regardless of injection pressure. However, flame luminosity of JP-8 was vanished more rapidly. The flame luminosity intensity analysis showed that fossil Diesel fuel had stronger flame luminosity overall and duration of visible flame luminosity was longer than JP-8. This implies that fossil Diesel fuel had more diffusion dominant combustion. From the flame luminosity variation rate analysis, decreasing rate of flame luminosity for JP-8 was higher compared with fossil Diesel fuel, showing that oxidation rate of JP-8 was much higher than fossil Diesel fuel. From FSF and FNH analysis, JP-8 showed lower value for both FSF and FNH in the later stage of combustion, because the later stage of combustion with JP-8 has less jet structure in comparison with fossil Diesel fuel. The flame temperature field from two-color thermometry showed that locally high temperature region existed with JP-8. KL factor distribution of JP-8 was distributed more uniformly with a relatively lower level of KL intensity in comparison with fossil Diesel fuel in the late stage of combustion.

[1]  Dimitrios C. Rakopoulos,et al.  Comparative Environmental Evaluation of JP-8 and Diesel Fuels Burned in Direct Injection (DI) or Indirect Injection (IDI) Diesel Engines and in a Laboratory Furnace , 2004 .

[2]  Kyle Kattke,et al.  Entrainment Waves in Diesel Jets , 2009 .

[3]  Sanghoon Kook,et al.  Visualization of Diesel Spray Penetration Cool-Flame Ignition High-Temperature Combustion and Soot Formation Using High-Speed Imaging. , 2009 .

[4]  Dimitrios T. Hountalas,et al.  Experimental investigation of the performance and exhaust emissions of a swirl chamber diesel engine using JP‐8 aviation fuel , 1997 .

[5]  R. A. White,et al.  Low Temperature Combustion within a Small Bore High Speed Direct Injection (HSDI) Diesel Engine , 2005 .

[6]  John E. Dec,et al.  The Effects of Injection Timing and Diluent Addition on Late-Combustion Soot Burnout in a Di Diese , 2000 .

[7]  Rolf D. Reitz,et al.  Two-color combustion visualization of single and split injections in a single-cylinder, heavy-duty D.I. diesel engine using an endoscope-based imaging system , 1999 .

[8]  Hua Zhao,et al.  Soot generation of diesel fuels with substantial amounts of oxygen-bearing compounds added , 2007 .

[9]  Paul C. Miles,et al.  The Influence of Swirl on HSDI Diesel Combustion at Moderate Speed and Load , 2000 .

[10]  Norimasa Iida,et al.  Effects of intake CO2 concentrations on fuel spray flame temperatures and soot formations , 2007 .

[11]  Mark P. B. Musculus,et al.  Measurements of the Influence of Soot Radiation on In-Cylinder Temperatures and Exhaust NOx in a Heavy-Duty DI Diesel Engine , 2005 .

[12]  N Ladommatos,et al.  Optical diagnostics for soot and temperature measurement in diesel engines , 1998 .

[13]  R. A. White,et al.  Influence of injection parameters on the transition from PCCI combustion to diffusion combustion in a small-bore HSDI diesel engine , 2009 .

[14]  E. C. Owens,et al.  USE OF AVIATION TURBINE FUEL JP-8 AS THE SINGLE FUEL ON THE BATTLEFIELD , 1989 .

[15]  Rolf D. Reitz,et al.  2-Color Thermometry Experiments and High-Speed Imaging of Multi-Mode Diesel Engine Combustion , 2005 .

[16]  Paul I. Lacey,et al.  Effect of Low-Lubricity Fuels on Diesel Injection Pumps - Part I: Field Performance , 1992 .

[17]  Bengt Johansson,et al.  Extending the Operating Region of Multi-Cylinder Partially Premixed Combustion using High Octane Number Fuel , 2011 .

[18]  Caroline L. Genzale,et al.  Effect of Ignition Delay on In-Cylinder Soot Characteristics of a Heavy Duty Diesel Engine Operating at Low Temperature Conditions , 2009 .

[19]  Zoran Filipi,et al.  Impact of military JP-8 fuel on heavy-duty diesel engine performance and emissions , 2007 .

[20]  Choongsik Bae,et al.  Application of JP-8 in a heavy duty diesel engine , 2011 .

[21]  D. Foster,et al.  Determination of Diesel Injector Nozzle Characteristics Using Two-Color Optical Pyrometry , 2002 .