Quantitative 2D LIF Measurements of Air/Fuel Ratios During the Intake Stroke in a Transparent SI Engine

Lawrenz, Wolfhard; Köhler, Jürgen; Meier, F.; Stolz, W.; Wirth, R.; Bloss, W. H.; Maly, R.; Wagner, E. C.; Zahn, M.

doi:10.4271/922320

Cited by 37 publications

(7 citation statements)

References 1 publication

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“…values (by $13 per cent) than 0.08ö at 3158 CA can be seen in the vicinity of the piston (see Fig. 9); these values are larger than those with open-valve injection start timing of TDC, in agreement with the observations of Baritaud and Heinze [12] and Lawrenz et al [13]. These higher values are considered to be the result of two phenomema: fuel drawn into the lower parts of the cylinder and segregated from the bulk air, before the subsequent vapour convection towards the central cylinder region during the later stages of compression, and evaporation of the larger droplets that impacted upon the piston crown during induction.…”

Section: Cycle-to-cycle Air=fuel Mixture Variationssupporting

confidence: 90%

Mixture preparation strategies in an optical four-valve port-injected gasoline engine

Gold

Arcoumanis

Whitelaw

et al. 2000

International Journal of Engine Research

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The mixture formation in a single-cylinder, optical port-injected gasoline engine was investigated for both closed- and open-valve injection strategies with a combination of phase Doppler anemometry, laser-induced fluorescence and Mie scattering and correlated with combustion development and exhaust emissions. Detailed crank angle resolved data of the flow and mixture distribution during induction and compression have revealed the advantages of early open-valve injection, in terms of extending the lean limit and maintaining satisfactory engine performance and HC/NOx emissions, achieved through charge stratification in the vicinity of the spark plug at the time of ignition.

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Section: Cycle-to-cycle Air=fuel Mixture Variationssupporting

confidence: 90%

Mixture preparation strategies in an optical four-valve port-injected gasoline engine

Gold

Arcoumanis

Whitelaw

et al. 2000

International Journal of Engine Research

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“…11,12 In fact several properties are sought for this tracer. First, light absorption needs to be at a wavelength achievable by a laser, and its fluorescence needs to be strong enough to be detected.…”

Section: Choice Of Tracermentioning

confidence: 99%

Development of a calibrated technique forin situinvestigation of air–fuel mixing in engines

Sercey¹,

Awcock²,

Heikal³

2006

The Imaging Science Journal

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This paper presents the role of imaging system design in developing an instrumentation technique to aid the validation of air-fuel mixing design hypotheses for use in next-generation internal combustion engines. In order to meet the challenge of extracting information from a research engine, the instrumentation system design was considered holistically through the application of 'scene constraint' principles. The objective is to obtain a two-dimensional map of fuel concentration in the cylinder, in order to be able to study the mixing process of air and fuel. To meet forthcoming emission regulations, a detailed understanding of this process is critical to the design of next generation (direct injection) gasoline engines. The carefully considered scene constraints, image acquisition and image analysis techniques described in this paper advance the laser-induced fluorescence technique to a point where it permits examination of cycle-to-cycle variability of the fuel-injection process, for example. A new approach to coping with fluorescence dependency on pressure and temperature, the choice of a fluorescence tracer, the determination of the optimum tracer concentration and the complete calibration methodology are described. The paper concludes with examples of calibrated measurements and evidence to indicate that information from this instrumentation technique method concurs with that derived from other experiments.

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“…D ifferent molecules react differently to quenching and thus the careful choice of the uorescing compound is a key point in obtaining quantitative LIF measurements [15,16]. In particular, standard gasoline is extremely sensitive to variation in pressure and temperature, restricting experiments to qualitative exercises.…”

Section: Choice Of Tracermentioning

confidence: 99%

On the use of laser-induced fluorescence for the measurement of in-cylinder air—fuel ratios

Sercey

Heikal

Gold

et al. 2002

Proceedings of the Institution of Mechanical Engineers, Part C:

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This paper presents the development of a new strategy for the calibration of air-fuel ratio measurements in engines by laser-induced fluorescence (LIF). After a brief introduction to the LIF technique, the paper highlights the structured approach undertaken to ensure that accurate quantitative measurements were produced. In particular, the new approach to coping with the fluorescence dependency on pressure and temperature, the issues related to the choice of a fluorescence tracer, the careful determination of the optimum tracer concentration and the complete calibration methodology are described, together with the resolution of some of the obstacles encountered. The paper concludes with some examples of calibrated measurements accompanied by a comparison of the results with combustion and emission performances. These results show a very good correlation.

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Quantitative 2D LIF Measurements of Air/Fuel Ratios During the Intake Stroke in a Transparent SI Engine

Cited by 37 publications

References 1 publication

Mixture preparation strategies in an optical four-valve port-injected gasoline engine

Mixture preparation strategies in an optical four-valve port-injected gasoline engine

Development of a calibrated technique forin situinvestigation of air–fuel mixing in engines

On the use of laser-induced fluorescence for the measurement of in-cylinder air—fuel ratios

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