This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Visual Analyses of End of Injection Liquid Structures and the Behaviour of Nozzle Surface-Bound Fuel in a Direct Injection Diesel Engine
ISSN: 0148-7191, e-ISSN: 2688-3627
Published January 15, 2019 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
For efficiency, the majority of modern diesel engines implement multiple injection strategies, increasing the frequency of transient injection phases and thus, end of injection (EOI) events. Recent advances in diagnostic techniques have identified several EOI phenomena pertinent to nozzle surface wetting as a precursor for deposit formation and a potential contributor towards pollutant emissions. To investigate the underlying processes, highspeed optical measurements at the microscopic scale were performed inside a motored diesel engine under low load/idling conditions. Visualisation of the injector nozzle surface and near nozzle region permitted an indepth analysis of the post-injection phenomena and the behaviour of fuel films on the nozzle surface when the engine is not fired. Inspection of the high-speed video data enabled an interpretation of the fluid dynamics leading to surface wetting, elucidating the mechanisms of deposition and spreading. As the needle re-seated, the abrupt pressure drop inhibited atomisation. Large, slow moving, liquid structures were released into the cylinder with the capability of impinging on nearby surfaces, creating localised fuel rich regions, or escaping through the exhaust and contributing towards un-burnt hydrocarbon emissions. Large ligaments remained attached to the nozzle, with some fluid subsequently breaking away while the remaining fuel adhering the nozzle retracted back causing surface wetting. The EOI event was succeeded by further surface wetting due to the expansion of orifice-trapped gas dislodging nozzle-residing fuel that then overspilled onto the external surface. The drop in in-cylinder pressure elicited bubbling within the surface-bound fuel, further increasing the films spreading rate. The resulting bubble agglomerations collapsed in large chain reactions, projecting more fuel into the cylinder. Finally, as the intake valves closed, high velocity intake air was diverted towards the nozzle removing the remaining surface-bound fuel. As a result, a large volume of fuel was released into the combustion chamber after the EOI causing deposits on nearby surfaces or getting released through the exhaust where it would contribute towards un-burnt hydrocarbon emissions. It is likely that the anticipated increase in in-cylinder pressure and temperature if the engine was fired would either reduce the time-scale of these event or completely inhibit them. However, understanding the behaviour of the surface-bound fuel within this environment will aid designs that control surface wetting, thus inhibiting nozzle coking with the capacity to control internal deposits.
CitationSykes, D., de Sercey, G., Gold, M., Pearson, R. et al., "Visual Analyses of End of Injection Liquid Structures and the Behaviour of Nozzle Surface-Bound Fuel in a Direct Injection Diesel Engine," SAE Technical Paper 2019-01-0059, 2019, https://doi.org/10.4271/2019-01-0059.
Data Sets - Support Documents
|[Unnamed Dataset 1]|
|[Unnamed Dataset 2]|
- Dieselnet, EU Cars and Light Trucks, in Emission Standards, (EcoPoint Inc., 2017).
- Rahman, M.M., Mohammed, K.M., and Bakar, R.A., “Effects of Air-Fuel Ratio and Engine Speed on Performance of Hydrogen Fueled Port Injection Engine,” Journal of Applied Sciences 9:1128-1134, 2009, doi:10.3923/jas.2009.1128.1134.
- Matsumoto, S., Yamada, K., and Date, K., “Concepts and Evolution of Injector for Common Rail System,” SAE Technical Paper 2012-01-1753, 2012, doi:10.4271/2012-01-1753.
- Delphi DFI 21 Diesel Common Rail Injectors, Report, Delphi, 2017, URL http://delphi.com/manufacturers/cv/powertrain/common-rail-systems/.
- Barker, J., Richards, P., Goodwin, M., and Wooler, J., “Influence of High Injection Pressure on Diesel Fuel Stability: A Study of Resultant Deposits,” SAE Int. J. Fuels Lubr. 2(1):877-884, 2009, doi:10.4271/2009-01-1877.
- Watkinson, A.P. and Wilson, D.I., “Chemical Reaction Fouling: A Review,” Experimental Thermal and Fluid Science 14:361-374, 1997, doi:10.1016/S0894-1777(96)00138-0.
- Birgel, A., Ladommatos, N., Aleiferis, P., Milovanovic, N. et al., “Investigations on Deposit Formation in the Holes of Diesel Injector Nozzles,” SAE Int. J. Fuels Lubr. 5(1):123-131, 2011, doi:10.4271/2011-01-1924.
- Lacey, P., Gail, S., Kientz, J.M., Benoist, G. et al., “Fuel Quality and Diesel Injector Deposits,” SAE Int. J. Fuels Lubr. 5(3):1187-1198, 2012, doi:10.4271/2012-01-1693.
- Caprotti, R., Breakspear, A., Graupner, O., and Klaua, T., “Detergency Requirements of Future Diesel Injection Systems,” SAE Technical Paper 2005-01-3901, 2005, doi:10.4271/2005-01-3901.
- Reid, J., Cook, S., and Barker, J., “Internal Injector Deposits from Sodium Sources,” SAE Int. J. Fuels Lubr. 7(2):436-444, 2014, doi:10.4271/2014-01-1388.
- Barker, J., Richard, P., Snape, C., and Meredith, W., “Diesel Injector Deposits - An Issue that Has Evolved with Engine Technology,” SAE Technical Paper 2011-01-1923, 2011, doi:10.4271/2011-01-1923.
- Magno, A., Mancaruso, E., Vaglieco, B.M., Florio, S. et al., “Study on Spray Injection and Combustion of Fouled and Cleaned Injectors by Means of 2-D Digital Imaging in a Transparent CR Diesel Engine,” SAE Technical Paper 2013-24-0062, 2013, doi:10.4271/2013-24-0062.
- Cracknell, R., Wardle, R., Pos, R., and Ganippa, L., “Effect of Diesel Injector Tip Deposits on Transient Spray Behavior,” in Internationaler Motorenkongress, 2016, doi:10.1007/978-3-658-12918-7_13.
- Caprotti, R., Bhatti, N., and Balfour, G., “Deposit Control in Modern Diesel Fuel Injection Systems,” SAE Int. J. Fuels Lubr. 3(2):901-915, 2010, doi:10.4271/2010-01-2250.
- Rounthwaite, N.J., Williams, R., Mcgivery, C., Jiang, J. et al., “A Chemical and Morphological Study of Diesel Injector Nozzle Deposits - Insights into Their Formation and Growth Mechanisms,” SAE Int. J. Fuels Lubr. 10(1):106-114, 2017, doi:10.4271/2017-01-0798.
- Tang, J., Pischinger, S., Lamping, M., Krfer, T. et al., “Coking Phenomena in Nozzle Orifices of Dl-Diesel Engines,” SAE Int. J. Fuels Lubr. 2(1):259-272, 2009, doi:10.4271/2009-01-0837.
- Stepien, Z., “The Reasons and Adverse Effect of Diesel Injector Deposit Formation,” Combustion Engines 156:20-29, 2014.
- Risberg, P.A. and Alfredsson, S., “The Effect of Zinc and other Metal Carboxylates on Nozzle Fouling,” SAE Technical Paper 2016-01-0837, 2016, doi:10.4271/2016-01-0837.
- Rakshit, S., “High Speed Flow Simulation in Fuel Injector Nozzles,” Master of Science in Mechanical Engineering, 2012, URL https://scholarworks.umass.edu/theses/942/.
- Li, D., Kang, Y., Ding, X., Wang, X. et al., “Effects of Nozzle Inner Surface Roughness on the Performance of Self-Resonating Cavitating Waterjets under Different Ambient Pressures,” Journal of Mechanical Engineering 63:92-102, 2017, doi:10.5545/sv-jme.2016. 3563.
- Suh, H.K. and Lee, C.S., “Effect of Cavitation in Nozzle Orifice on the Diesel Fuel Atomization Characteristics,” International Journal of Heat and Fluid Flow 29:1001-1009, 2008, doi:10.1016/j.ijheatfluidflow.2008.03.014.
- Barker, J., Cook, S., and Richards, P., “Sodium Contamination of Diesel Fuel, its Interaction with Fuel Additives and the Resultant Effects on Filter Plugging and Injector Fouling,” SAE Int. J. Fuels Lubr. 6(3):826-838, 2013, doi:10.4271/2013-01-2687.
- Barsic, N.J. and Humke, A.L., “Performance and Emissions Characteristics of a Naturally Aspirated Diesel Engine with Vegetable Oil Fuels,” SAE Technical Paper 810262, 1981, doi:10.4271/810262.
- Li, D., Kang, Y., Wang, X., Ding, X. et al., “Effects of Nozzle Inner Surface Roughness on the Cavitation Erosion Characteristics of High Speed Submerged Jets,” Experimental Thermal and Fluid Science 74:444-452, 2016, doi::10.1016/j.expthermflusci. 2016.01.009.
- Koci, C.P., Dempsey, A., Nudd, J., and Knier, B., “Understanding Hydrocarbon Emissions in Heavy Duty Diesel Engines Combining Experimental and Computational Methods,” SAE Int. J. Engines 10(3):1093-1109, 2017, doi:10.4271/2017-01-0703.
- Turner, J.E., Stetsyuk, V., Crua, C., Pearson, R.J. et al., “The Effect of Operating Conditions on Post-Injection Fuel Discharge in an Optical Engine,” in 13th Triennial International Conference on Liquid Atomization and Spray Systems, 2015, URL https://iclass2015.tw/index.php.
- Turner, J., Sykes, D., Sercey, G.D., Stetsyuk, V. et al., “A Quantitative Analysis of Nozzle Surface Bound Fuel for Diesel Injectors,” in ILASS 2017 - 28th European Conference on Liquid Atomization and Spray Systems, 2017, doi:10.4995/ILASS2017.2017.4661.
- Pos, R., Avulapati, M., Wardle, R., Cracknell, R. et al., “Combustion of Ligaments and Droplets Expelled after the End of Injection in a Multi-Hole Diesel Injector,” Fuel 197:459-466, 2017, doi:10.1016/j.fuel.2017.02.048.
- Crua, C., Heikal, M.R., and Gold, M.R., “Microscopic Imaging of the Initial Stage of Diesel Spray Formation,” Fuel 157:140-150, 2015, doi::10.1016/j.fuel.2015.04. 041.
- Swantek, A.B., Duke, D., Tilocco, F.Z., Sovis, N. et al., “End of Injection, Mass Expulsion Behaviors in Single Hole Diesel Fuel Injectors,” in ILASS Americas 26th Annual Conference on Liquid Atomization and Spray Systems, 2014, URL http://www.ilass.org/2/index.html.
- Swantek, A.B., Kastengren, A.L., Duke, D., Tilocco, F.Z. et al., “A Further Examination of Fuel Dribble from Single Hole Diesel Nozzles,” in ILASS Europe 26th Annual Conference, 2014, URL http://ilasseurope.org/events/26th-ilass-europe-2014/.
- Moon, S., Huang, W., Li, Z., and Wang, J., “End-Of-Injection Fuel Dribble of Multi-Hole Diesel Injector: Comprehensive Investigation of Phenomenon and Discussion on Control Strategy,” Applied Energy 179:7-16, 2016, doi:10.1016/j.apenergy.2016.06.116.
- Eagle, W.E. and Musculus, M.P.B., “Cinema-Stereo Imaging of Fuel Dribble after the End of Injection in an Optical Heavy-Duty Diesel Engine,” in UPV (Ed.), Thiesel 2014 Conference on Thermo- and Fluid Dynamic Processes in Direct Injection Engines, 2014, URL 10.1177/1468087414560307.
- Lockett, R., Jeshani, M., Makri, K., and Price, R., “An Optical Characterization of Atomization in Non-Evaporating Diesel Sprays,” SAE Technical Paper 2016-01-0865, 2016, doi:10.4271/2016-01-0865.
- Kirsch, V., Reddemann, M.A., Palmer, J., and Kneer, R., “Zooming into Primary Breakup Mechanisms of High-Pressure Automotive Sprays,” in ILASS Europe: Conference on Liquid Atomization and Spray Systems, 2017, doi:10.4995/ILASS2017.2017.4603.
- Battistoni, M., Xue, Q., and Som, S., “Large-Eddy Simulation (Les) of Spray Transients: Start and End of Injection Phenomena,” Oil Gas Sci. Technol. Rev. IFP Energies nouvelles 71:4, 2016, doi:10.2516/ogst/2015024.
- Anantharaman, S. and Baskaran, M., “A Research on Factors Affecting Nozzle Tip Temperature in Diesel Engines,” SAE Technical Paper 2015-01-2791, 2015, doi:10.4271/2015-01-2791.
- Leuthel, R., Pfitzner, M., and Frobenius, M., “Numerical Study of Thermal-Fluid-Interaction in a Diesel Fuel Injector,” SAE Technical Paper 2008-01-2760, 2008, doi:10.4271/2008-01-2760.
- Sazhin, S.S., Qubeissi, M.A., Nasiri, R., Gunko, V.M. et al., “A Multi-Dimensional Quasi-Discrete Model for the Analysis of Diesel Fuel Droplet Heating and Evaporation,” Fuel 129:238-266, 2014, doi:10.1016/j.fuel.2014.03.028.
- Liley, P.E., Hewitt, G.F., and Beaton, C.F., Physical Property Data for the Design Engineer (New York: Hemisphere Pub. Corp, 1989).
- Bonn, D., Eggers, J., Indekeu, J., Meunier, J. et al., “Wetting and Spreading,” Reviews of Modern Physics 81:739-805, 2009, doi:10.1103/RevModPhys.81.739.
- Brennen, C., “Cavitation and Bubble Dynamics,” 44, 1995, doi:10.1017/CBO9781107338760.
- Koci, C.P., Ra, Y., Krieger, R., Andrie, M. et al., “Multiple-Event Fuel Injection Investigations in a Highly-Dilute Diesel Low Temperature Combustion Regime,” SAE International Journal of Engines 2(1):837-857, 2009, doi:10.4271/2009-01-0925.
- Zhu, J., Kuti, O.A., and Nishida, K., “Effects of Injection Pressure and Ambient Gas Density on Fuel - Ambient Gas Mixing and Combustion Characteristics of D.I. Diesel Spray,” SAE Technical Paper 2011-01-1819, 2011, doi:10.4271/2011-01-1819.