This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Evaluation of the Influence of Injector Type in a Four-Valve Engine
Annotation ability available
Sector:
Language:
English
Abstract
The performance of a four-valve engine operating with combustion in all cylinders has been determined in terms of indicated mean-effective pressure, drivability and concentrations of unburned hydrocarbon in the exhaust gases with a stoichiometric mixture of gasoline and air and four injectors including two with air assist. In addition, size and velocity characteristics of the fuel sprays were measured with a phase-Doppler velocimeter outside and inside the engine.
With operation at a steady rotational speed of 1200 rpm, the indicated mean- effective cylinder pressure and its covariance were found to be nearly constant with the initiation of injection from 150 to 600 degrees of crank angle after top-dead-centre of intake. The reduction in mean effective pressure with injection with the valves open between 30 and 90 degrees, previously observed with a production double-jet injector, was also found with air assist, with a smaller reduction when the air-assisted spray corresponded to a single and narrow cone so that more fuel impinged on the walls in the region of the port divider. The averaged Sauter mean diameter of droplets from the air-assisted injectors was found to decrease with manifold depression and at low engine load it was of the order of 50 μm and in contrast to the values in excess of 100 μm with a production type.
Unsteady operation of the engine involved adjustment of throttle and injection period over ten cycles so that the load was changed at constant speed. With the injection schedule of a production management system, the instantaneous equivalence ratios were up to 12 % below stoichiometric and the deficiency was smaller with injection with the valves open and mono-jet sprays. Experiments with control of the fuel injected during the transient showed that it was possible to reduce the duration and magnitude of the lean excursions as can be required in order to maintain the efficiency of the catalytic converter.
Recommended Content
Authors
Topic
Citation
Brehm, C., Carabateas, N., Cousyn, B., Mangano, R. et al., "Evaluation of the Influence of Injector Type in a Four-Valve Engine," SAE Technical Paper 961998, 1996, https://doi.org/10.4271/961998.Also In
References
- Chappuis, S. Cousyn, B. Posylkin, M. Vannobel, F. Whitelaw, J. H. 1996 Velocity and drop-size distributions in a four-valve production engine Exp in Fluids
- Vannobel, F. Robart, D. Dementhon, J.-B. Whitelaw, J.H. 1994 Velocity and drop-size distributions in a two-valve production firing engine Proc COMODIA 371 378
- Posylkin, M. Taylor, A.M.K.P. Vannobel, F. Whitelaw, J.H. 1994 Manifold injection and the origin of dropets at the exit of a valve SAE Paper 941989
- Cousyn, B. Posylkin, M. Vannobel, F. Whitelaw, J.H. 1995 Droplet characteristics in two cylinders of a firing spark-ignition engine SAE Paper 952466
- Bandel, W. Fraidl, G. Mikulic, L.A. Carstensen, H. Quissek, F. 1989 Investigation of mixture preparation and charge motion effects on the combustion of fast-burn gasoline engines SAE paper 890160
- Mikulic, L.A. Quissek, F. Fraidl, G.K. 1990 Development of low emission high performance four valve engines SAE paper 900227
- Horie, K. Nishizawa, K. Ogawa, T. Akazaki, S. Miura, K. 1992 Development of a high fuel economy and high performance four-valve lean burn engine SAE paper 920455
- Winklhofer, E. Fraidl, G.K. Plimon, A. 1992 Monitoring of gasoline fuel distribution in a research engine Proc. IMechE 206 107
- Alkidas, A.C. 1994 The effects of fuel preparation on hydrocarbon emissions of a SI engine operating under steady-state conditions SAE Paper 941959
- Posylkin, M. Taylor, A.M.K.P. Whitelaw, J.H. 1995 Size and velocity characteristics of fuel droplets in the valve-curtain area of a straight, steady-flow inlet manifold Applications of Laser Techniques to Fluid Mechanics 7 132
- Hardalupas, Y. Taylor, A.M.K.P. Whitelaw, J.H. Ishii, K. Miyano, H. Urata, Y. 1995 Influence of injection timing on in-cylinder liquid and vapour fuel distribution in a Honda VTEC-E engine SAE Paper 950507
- Brown, C.N. Ladomatos, N. 1991 The effects of mixture preparation and trapped residuals on the performance of a spark-ignition engine with air-shrouded port injectors, at low load and low speed Proc. IMechE 205 17
- Almkvist, G. Denbrat, I. Josefsson, G. Magnusson, 1. 1995 Measurements of fuel film thickness in the inlet port of an SI engine by laser induced fluorescence SAE Paper 952483
- Fulcher, SK Gajdeczko, B.F. Felton, P.G. Bracco, F.V. 1995 The effects of fuel atomisation, vaporisation and mixing on the cold start UHC emissions with a contemporary SI engine with intake manifold injection SAE Paper 952482
- Lancaster, D.R. Krieger, R.B. Lienesch, J.H. 1975 Measurement and analysis of engine pressure data SAE Paper 750026
- Heywood, J.B. 1988 Internal combustion engines fundamentals McGraw-Hill Book Co. Singapore
- Tate, R.W. 1982 Some Problems Associated with the Accurate Representation of Droplet Size Distributions Proc. of 2nd Int'l Conf. on Liquid Atomisation and Spray Systems (ICLASS) Wisconsin, USA
- Migl, M. 1995 Effects of equivalence ratio, injection timing and fuel spray characterisation on combustion performance and hydrocarbon emissions during cold start and warm-up phases of a four-valve SI engine
- Posylkin, M. 1996 Mixture preparation in spark-ignition engine University of London
- Miller, M.J. Nightingale, C.J.E. 1990 Measurement of the changes in mixture preparation that occur during flow past the inlet valve of an SI engine IMechE Int'l Conference on Automotive Power Systems Chester 10 12 September Paper C394/004