This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
A Study on Droplets Evaporation at Diesel Spray Boundary during Ignition Delay Period
Technical Paper
2007-01-1893
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Diesel spray evaporation in a high pressure and high ambient temperature close to actual diesel engine condition was investigated in this study. A nano-spark shadowgraph photography technique and a rapid compression machine were applied in this experiment. By using this method, relatively clear image of liquid phase, vapor phase and droplets was obtained. In order to quantify the spray characteristics in the spray liquid area and vapor phase area, an image analysis method was applied. An algorithm was developed to quantify the droplets size and number of the droplets characteristic in the vapor phase.
Experimental results have revealed that the injection pressure and the ambient temperature do not affect the spray penetration length apparently. In the case of ambient temperature Ti = 700K, the liquid core is observed in the region near the spray axis. Meanwhile, the vapor exists mostly in the outer region in the middle of the spray. However, at Ti = 950K, the vapor phase expands and dominates the spray tip region. This is because high ambient temperature promotes the evaporation, and consequently, instantaneous evaporation on a fuel spray occurs as soon as the fuel injection.
According to close reference of vapor phase at the spray boundary region, many dark spots can be visualized inside the vapor region. These dark spots seem to indicate the existence of liquid droplets inside the vapor phase. When the fuel is injected into the spray chamber, droplets at outer region of the spray are flying away and evaporate simultaneously. In the case of the evaporation process at high ambient temperature and high injection pressure, the evaporation speed is expedited exceeding the droplets velocity thus trapped the flying droplets in vapor region.
Recommended Content
Authors
Citation
Adam, A., Inukai, N., Kidoguchi, Y., Miwa, K. et al., "A Study on Droplets Evaporation at Diesel Spray Boundary during Ignition Delay Period," SAE Technical Paper 2007-01-1893, 2007, https://doi.org/10.4271/2007-01-1893.Also In
References
- Hiroyasu H. Arai, M. “Structures of Fuel Sprays in Diesel Engines” SAE Paper 900475 1990
- Yeom J.K. et al. “The Structure Analysis of Evaporative Diesel Spray” SAE Paper 2002-01-0498 2002
- Pierpont D.A. Reitz R.D. “Effect of Injection Pressure and Nozzle Geometry on DI Diesel Emissions and Performance” SAE Paper 950604 1995
- Su T.F. et al. “Effects of Injection Pressure and Nozzle Geometry on Spray SMD and D.I Emissions” SAE Paper 952360 1995
- Arregle J. Pastor J.V. Ruiz S. “The Influence of Injection Parameters on Diesel Spray Characteristics” SAE Paper 1999-01-0200 1999
- Blessing M. et al. “Analysis of Flow and Cavitation Phenomena in Diesel Injection Nozzles and Its Effects on Spray and Mixture Formation” SAE Paper 2003-01-1358 2003
- Suzuki M. Nishida K. Hiroyasu H. “Simultaneous Concentration Measurement of Vapor and Liquid in an Evaporating Diesel Spray” SAE Paper 930863 1993
- Kamimoto T. et al. “Measurement of Droplet Diameter and Fuel Concentration in a Non-Evaporating Diesel Spray by Means of an Image Analysis of Shadow Photographs” SAE Paper 840276 1984
- Ha J.Y. et al. “Experimental Investigation of The Entrainment into Diesel Spray” SAE Paper 841078 1984
- Arai M. “Spray and Spray Combustion (Formation of Diesel Spray and Its Ignition Delay)” Engine Technology 2 6 82 86 2000
- Mohammadi A. Kidoguchi Y. Miwa K. “Effect of Injection Parameters and Wall-Impingement on Atomization and Gas Entrainment Processes in Diesel Sprays” SAE Paper 2002-01-0497 2002
- Miwa K. Ohmija T. Nishitani T. “A Study of the Ignition Delay of Diesel Fuel Spray Using a Rapid Compression Machine” JSME Int. Journal, Series 2 31 1 166 173 1998
- Miyashiro S. et al. “Optical Measurements of Liquid Sprays with New Nanosecond Spark Light Source” 8th Int. Sympo. on Flow Visualization 98 Italy 1998
- Mohammadi A. et al. “Investigation of Droplets and Ambient Gas Interaction in a Diesel Spray Using a Nano-Spark Photography Method” SAE Paper 981073 1998
- Miwa K. Ishiyama T. Horikoshi O. “A Study on Ignition Process of Diesel Sprays” JSME Int. Journal, Series B 38 3 483 489 1995
- Kim T. et al. “Evaporating Spray Concentration Measurements from Small and Medium Bore Diesel Injectors” SAE Paper 2002-01-0219 2002
- Desantes J.M. et al. “Experimental Characterization of the Liquid Phase Penetration on Evaporating Diesel Sprays” SAE Paper 2005-01-2095 2005
- Dan T. et al. “Effect of Ambient Gas Viscosity on the Structure of Diesel Fuel Spray” JSME J. Series B 62 599 327 333 1996
- Miwa K. Mohammadi A. Kidoguchi Y. “A Study on Thermal Decomposition of Fuels and NOx Formation in Diesel Combustion Using a Total Gas Sampling Technique” Int. J Engine Research 2 3 189 198 2001