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Rickeard, David
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A Mathematical Model for the Vapour Composition and Flammability of Gasoline - Diesel Mixtures in a Fuel Tank

Concawe-Heather Hamje, David Rickeard
ENI Spa-Leonardo Pellegrini
Published 2017-10-08 by SAE International in United States
Low Temperature Combustion using compression ignition may provide high efficiency combined with low emissions of oxides of nitrogen and soot. This process is facilitated by fuels with lower cetane number than standard diesel fuel. Mixtures of gasoline and diesel (“dieseline”) may be one way of achieving this, but a practical concern is the flammability of the headspace vapours in the vehicle fuel tank. Gasoline is much more volatile than diesel so, at most ambient temperatures, the headspace vapours in the tank are too rich to burn. A gasoline/diesel mixture in a fuel tank therefore can result in a flammable headspace, particularly at cold ambient temperatures. A mathematical model is presented that predicts the flammability of the headspace vapours in a tank containing mixtures of gasoline and diesel fuel. Fourteen hydrocarbons and ethanol represent the volatile components. Heavier components are treated as non-volatile diluents in the liquid phase. The non-ideality of the blends of hydrocarbons and ethanol is accounted for using activity coefficients. Predictions for dry vapour pressure equivalent (DVPE), vapour phase composition and flammability are…
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Vapour Space Flammability Considerations for Gasoline Compression Ignition Vehicles Operating on “Dieseline” Blends.

SAE International Journal of Fuels and Lubricants

Concawe-Heather Hamje, David Rickeard
ENI Spa-Leonardo Pellegrini
  • Journal Article
  • 2016-01-2266
Published 2016-10-17 by SAE International in United States
Gasoline Compression Ignition (GCI) has been identified as a technology which could give both high efficiency and relatively low engine-out emissions. The introduction of any new vehicle technology requires widespread availability of appropriate fuels. It would be ideal therefore if GCI vehicles were able to operate using the standard grade of gasoline that is available at the pump. However, in spite of recent progress, operation at idle and low loads still remains a formidable challenge, given the relatively low autoignition reactivity of conventional gasoline at these conditions. One conceivable solution would be to use both diesel and gasoline, either in separate tanks or blended as a single fuel (“dieseline”). However, with this latter option, a major concern for dieseline would be whether a flammable mixture could exist in the vapour space in the fuel tank. It is expected that in a practical scenario, the ambient temperature would generally exceed the Lower Flammability Limit (LFL) temperature of diesel/gasoline blends. A non-flammable vapour could still be assured, however, if the temperature in the fuel tank were above…
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Effect of Octane on the Performance of Two Gasoline Direct Injection Passenger Cars

BP International Ltd-John Williams
Concawe-David Rickeard, Heather Hamje
Published 2015-04-14 by SAE International in United States
The performance aspect of gasoline combustion has traditionally been measured using Research Octane Number (RON) and Motor Octane Number (MON) which describe antiknock performance under different conditions. Recent literature suggests that MON is less important than RON in modern cars and a relaxation in the MON specification could improve vehicle performance, while also helping refiners in the production of gasoline. At the same time, for the same octane number change, increasing RON appears to provide more benefit to engine power and acceleration than reducing MON. It has also been suggested that there could be fuel efficiency benefits (on a tank to wheels basis) for specially adapted engines, for example, operating at higher compression ratio, on very high RON (100+). Other workers have advocated the use of an octane index (OI) which incorporates both RON and MON to give an indication of octane quality.The objective of this study was to investigate the effect of RON and MON on the power and acceleration performance of two Euro 4 gasoline vehicles under full throttle acceleration conditions. Fifteen fuels…
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Modelling a Gasoline Compression Ignition (GCI) Engine Concept

Concawe-Roger F. Cracknell, Javier Ariztegui, Thomas Dubois, Heather Hamje, Leonardo Pellegrini, David Rickeard, Kenneth D. Rose
FEV GmbH-Karl Alexander Heufer, Hans Rohs
Published 2014-04-01 by SAE International in United States
Future engines and vehicles will be required to reduce both regulated and CO2 emissions. To achieve this performance, they will be configured with advanced hardware and engine control technology that will enable their operation on a broader range of fuel properties than today.Previous work has shown that an advanced compression ignition bench engine can operate successfully on a European market gasoline over a range of speed/load conditions while achieving diesel-like engine efficiency and acceptable regulated emissions and noise levels. Stable Gasoline CI (GCI) combustion using a European market gasoline was achieved at high to medium engine loads but combustion at lower loads was very sensitive to EGR rates, leading to longer ignition delays and a steep cylinder pressure rise. In general, the simultaneous optimisation of engine-out emissions and combustion noise was a considerable challenge and the engine could not be operated successfully at lower load conditions without an unrealistic amount of boost pressure.To identify ways to improve the lower load performance of a GCI engine concept, Computational Fluid Dynamics and KIVA simulations have now been…
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Fuel Effects on Regulated Emissions from Modern Gasoline Vehicles

BP Global Fuels Technology-Roberto Bazzani
CONCAWE-Neville Thompson
Published 2004-06-08 by SAE International in United States
The influence of gasoline quality on exhaust emissions has been evaluated using four modern European gasoline cars with advanced features designed to improve fuel economy and CO2 emissions, including stoichiometric direct injection, lean direct injection and MPI with variable valve actuation.Fuel effects studied included sulphur content, evaluated over a range from 4 to 148 mg/kg, and other gasoline properties, including aromatics content, olefins content, volatility and final boiling point (FBP).All four cars achieved very low emissions levels, with some clear differences between the vehicle technologies. Even at these low emissions levels, all four cars showed very little short-term sensitivity to gasoline sulphur content. The measured effects of the other gasoline properties were small and often conflicting, with differing directional responses for different vehicles and emissions.
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