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Influence of Air Assisted Fuel Injection on the Mixing Preparation within the Intake Ports of SI-Engines
ISSN: 0148-7191, e-ISSN: 2688-3627
Published October 19, 1998 by SAE International in United States
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This work investigates the mixture formation process in a SI engine with air-assisted port fuel injection. The combination of this injection method with low flow velocities and wall temperatures, typical of engine starting and warm-up conditions, results in the build-up of a fuel film along the walls of the port. This in turn results in increased fuel consumption and high unburned hydrocarbon emissions.
This investigation concluded that with the application of air-assisted injectors, the mixture formation process could be improved with a resulting reduction of the fuel-film build-up in the intake ports. Comparative measurements of the drop size distribution from conventional and air-assisted injectors showed that even very small amounts of air resulted in better fuel atomization. An experimental analysis of the effect of unsteady air flow on spray dispersion and fuel film creation characteristics of air supported injectors was undertaken for a straight test section. Measurements of the fuel-film in the intake port of a mass production cylinder head showed that a considerable decrease of the development of such fuel-films is possible through the use of air-assisted injectors.
Through systematic analysis of the flow parameters in the test section it was possible to evaluate their effects on atomization and film generation. The comparison of this analysis with the measurements taken on the production cylinder head show the transferability of the model to the complex conditions in the intake port.
CitationMaier, G., Wittig, S., and Manz, P., "Influence of Air Assisted Fuel Injection on the Mixing Preparation within the Intake Ports of SI-Engines," SAE Technical Paper 982523, 1998, https://doi.org/10.4271/982523.
- Sches C. Guilain S. Maroteaux F. Modeling of the Fuel Behaviour in the Intake Manifold of a Port-Injected Spark-Ignition Engine SAE 972992 1997
- Lippert A.M. Reitz R.D. Modeling of Multicomponent Fuels Using Continous Distributions with Application to Droplet Evaporation and Sprays SAE 972882 1997
- Bauer W. Balun P. Heywood J.B. Heat Transfer and Mixture Vaporization in Intake Port of Spark-Ignition Engine SAE 972983 1997
- Almkvist G. Dahlberg M. Measurement of Fuel Droplet Dynamics in the Inlet Port of an SI Engine Under Firing Conditions SAE 961924 1996
- Almkvist G. Denbratt J. Josefsson G. Magnusson J. Measurements of Fuel Film Thickness in the Inlet Port of an SI Engine by Laser Induced Fluorescence SAE 952483 1995
- Samenfink, W. Elsäßer, A. Dullenkopf, K. Wittig, S. Droplet Interaction with Shear-driven Liquid Films: High Quality Measurements of the Deposited Mass Fraction Proceedings of the 13th Annual Conference on Liquid Atomization and Spray Systems (ilass97) July 9 - 11 Florence, Italy 1997
- Samenfink, W. Hallmann, M. Elsäßer, A. Wittig, S. Secondary Break-up of Liquid Droplets: Experimental Investigation for a Numerical Description Proceedings of the Sixth International Conference on Liquid Atomization and Spray Systems (iclass94) Rouen, France 1994
- Wittig, S. Müller, H. Hallmann, M. Bellmann, H. Elsäßer, A. Samenfink, W. MTZ - Motortechnische Zeit-schrift 57 12 688 699 1996
- Roßkamp, H. Willmann, M. Wittig. S. 1997 Computation of two-phase flows in low-NOx combustor premix ducts utilizing fuel film evaporation ASME-Paper 97-GT-226
- Manz P.-W. Operating a Gasoline Engine at Constant low Temperature Conditions. The Influence of Different Fuel Droplet Sizes SAE 961999 1996
- Lefebvre, A.H. Atomization and Sprays 1989 Taylor and Francis 234 238