International Scientific Journal

External Links


The effect of three injection rate modes on fuel spray-wall impingement and combustion process in a direct injection diesel engine is investigated in present work. A three-dimensional computational fluid dynamics model for flow field, spray, spray-wall interactions, combustion, and emission formation processes have been used to carry out the computations. The optimized omega combustion chamber geometry was used in the diesel engine model instead of baseline cylindrical geometry and the results were verified for this improved combustion chamber geometry. Results for different injection modes indicate that using the ramp injection rate curve, the spray-wall impinging is increased due to higher injection rate at the end of injection duration. Also the increased in-cylinder temperature, piston surface temperature and higher turbulence intensity leads to enhanced wall-film evaporation. Soot mass fraction also decreases due to improved air-fuel mixing and evaporation of wall-film by reduction of the fuel rich zones especially in the impingement regions. Results for different injection modes indicate that using the ramp injection rate shape slightly retards the combustion process and improves combustion characteristics while maintaining lower NOx and considerably lower soot emissions compared to the boot and rectangle injection modes. Also, in this injection mode, because of the high pressure injection, higher spray droplet velocities (higher Weber number) and increased wall spray height than the other modes, it could be said that the dominant impingement regime may be the splashing regime. The results of model for baseline diesel engine are compared with the corresponding experimental data and show good levels of agreement.
PAPER REVISED: 2010-08-19
PAPER ACCEPTED: 2010-10-01
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2010, VOLUME 14, ISSUE Issue 4, PAGES [1039 - 1049]
  1. Jafarmadar, S, et al., Numerical Investigation of the Effect of Fuel Preheating on Combustion Process and Emission in a Direct Injection Diesel Engine, 6th Conference International Combustion Engine - CICE, 2009, Tehran, Iran, Paper No. 1166
  2. Heywood, J. B, Internal Combustion Engine Fundamentals, McGraw Hill Book Company, New York, USA, 1988
  3. Gosman, A. D., Computer Modeling of Flow and Heat Transfer in Engines, Progress and Prospects, Imperil College of Science and Technology, London, 1988
  4. Jeske Felix, R., et al. Modeling of the Natural Gas Injection Process in a Two-Stroke Diesel Engine, SAE paper 920192
  5. Patterson, M. A., et al., Modeling the Effects of Fuel Injection Characteristics on Diesel Engine Soot and NOx Emissions, SAE paper 940523
  6. Henein, N. A., et al., Characteristics of a Common Rail Diesel Injection System under Pilot and Post Injection Modes, SAE paper 2002-01-0218
  7. Naoki, Sh., et al., Dual Mode Combustion Concept with Premixed Diesel Combustion by Direct Injection Near Top Dead Center, SAE paper 2003-01-0742
  8. Rottmann, M., et al., Injection Rate Shaping Investigations on a Small-Bore DI Diesel Engine, SAE paper 2009-01-0850
  9. Nishimura, T., Effects of Fuel Injection Rate on Combustion and Emission in a DI Diesel Engine, SAE paper 981929
  10. 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
  11. Allocca, L., De Vita, A., Di Angelo, L., Wall-Impingement Analysis of a Spray from a Common Rail Injection System for Diesel Engines, Proceedings, THIESEL 2002 Conference on Thermo- and Fluid Dynamic Processes in Diesel Engines, Instituto Motori CNR, Italy, pp. 67-76
  12. Jafarmadar. S., et al., Modeling the Effect of Spray/Wall Impingement on Combustion Process and Emission of DI Diesel Engine, Journal of Thermal Science, 13 (2009), 3, pp. 23-34
  13. Pirouzpanah, V, Kashani, B. O., Prediction of Major Pollutants Emission in Direct-Injection Dual-Fuel Diesel and Natural Gas Engines, SAE paper 1999-01-0841
  14. ***, AVL FIRE User Manual, V. 3, 2006
  15. Baumgarten, C., Mixture Formation in Internal Combustion Engines, Springer Publications, 2006
  16. Naber, J. D., Reitz, R. D., Modeling Engine Spray/Wall Impingement, SAE paper 880107
  17. Mundo, C., Sommerfeld, M., Tropea, C., Droplet-Wall Collisions: Experimental Studies of the Deformation and Breakup Process, Int. J. Multiphase Flow, 21 (1995), 2, pp. 151-173
  18. Mundo, C., Sommerfeld, M., Tropea, C., Experimental Studies of the Deposition and Splashing of Small Liquid Droplets Impinging on a Flat Surface, Proceedings, 6th International Conference on Liquid Atomization and Spray Systems, Rouen, France, 1994
  19. Jafarmadar, S., Zehni, A., Multi-Dimensional Modeling of the Effects of Split Injection Scheme on Combustion and Emissions of Direct-Injection Diesel Engines at Full Load State, International Journal of Engineering, Transactions A: Basics, 22 (2009), 4, pp. 369-378

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence