Analysis of Combustion Process in Cold Operation with a Low Compression Ratio Diesel Engine

Perrin, H.; Dumas, J. P.; Laget, Olivier; Walter, Bruno

doi:10.4271/2010-01-1267

Cited by 20 publications

(12 citation statements)

References 17 publications

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“…Various studies [1,2,3,5,6,7,8] have concluded that cold start performance can be greatly assisted by the introduction of a pilot injection, promoting cool flame reactions creating an activated environment in which to inject the main. To examine why extra pilot injections have a positive impact on heat release characteristics in-cylinder fuel distribution has been investigated using Kiva3v.…”

Section: Resultsmentioning

confidence: 99%

“…Findings reported by Pacaud et al [3] and MacMillan et al [4,5] have highlighted the importance for further work to investigate cause of poor cold idle stability and the development of suitable techniques to make improvements. The importance of cool flame and hot pre-mixed combustion in promoting reliable combustion of fuel delivered in the main injection was indicated by Perrin et al [6]. Increasing the number of injector holes, for an equal nozzle flow rate, enhances the air entrainment assisting with fuel air mixing [7].…”

Section: Introductionmentioning

confidence: 99%

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CFD Investigation on the Influence of In-Cylinder Mixture Distribution from Multiple Pilot Injections on Cold Idle Behaviour of a Light Duty Diesel Engine

Rocca

MacMillan

Shayler

et al. 2014

SAE Technical Paper Series

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Cold idle operation of a modern design light duty diesel engine and the effect of multiple pilot injections on stability were investigated. The investigation was initially carried out experimentally at 1000rpm and at −20°C. Benefits of mixture preparation were initially explored by a heat release analysis. Kiva 3v was then used to model the effect of multiple pilots on in-cylinder mixture distribution. A 60° sector of mesh was used taking advantage of rotational symmetry. The combustion system and injector arrangements mimic the HPCR diesel engine used in the experimental investigation. The CFD analysis covers evolutions from intake valve closing to start of combustion. The number of injections was varied from 1 to 4, but the total fuel injected was kept constant at 17mm 3 /stroke. Start of main injection timing was fixed at 7.5°BTDC. The experimental study shows that increasing the number of pilots improves stability and leads to fuel preparation resulting in higher initial peak rate of heat release. CFD results show that multiple pilot injections are capable of better fuel distribution; noticeable by injecting just one pilot compared to no pilot. A further pilot increases the surface area of the vapour cloud to a greater extent. Three pilots allow for fuel to be well distributed in the full bowl with no lean regions; a greater proportion of the fuel is exposed to the glow plug temperature. The glow plug is enclosed by a fuel cloud over a longer period of time as the number of pilot injections is increased.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

CFD Investigation on the Influence of In-Cylinder Mixture Distribution from Multiple Pilot Injections on Cold Idle Behaviour of a Light Duty Diesel Engine

Rocca

MacMillan

Shayler

et al. 2014

SAE Technical Paper Series

View full text Add to dashboard Cite

show abstract

“…Laget et al [6] show a more systematic approach to the problem in which in-cylinder analysis, endoscopic visualization and CFD modeling are coupled in order to identify the pre-glowing glow plug duration, nozzle tip protrusion, injector spray angle and cranking speed as key parameters with influence on startability. Later, a more detailed analysis of the combustion sequence have been presented by Perrin et al [11], in which the location of the first ignition spots are shown to appear in the vicinity of the glow plug, together with the influence of some other parameters like swirl motion and injection pressure. Similar work has been presented by Chartier et al [12], who show how combustion starts close to the glow plug and does not spread to the whole chamber.…”

Section: Introductionmentioning

confidence: 99%

Ignition and combustion development for high speed direct injection diesel engines under low temperature cold start conditions

Pastor

García-Oliver

Ramírez-Hernández

2011

Fuel

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Visualization results show that pilot ignition occurs in the vicinity of the glow plug, and strongly influences main combustion initiation. Main combustion starts from the pilot flame, and propagates to the rest of the combustion chamber showing a strong visible reaction zone. After end of main injection, the rapid leaning of the mixture suppresses the strong radiation, and OH radiation is observed to progress to the rest of the combustion chamber. The combustion process shows a strong scattering, which has been quantified

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“…To address the issues that low-compression-ratio engines encounter during the start-up process, some researchers have focused on studying the combustion characteristics of and the improvements to high-altitude engines. Perrin and co-workers 11,12 used a low-compression-ratio (13.7:1) diesel engine at −25 °C to study the experimental combustion process and compared their results with those obtained after using the original conventional-compression-ratio engine. Then, complete recalibration of the injection settings was carried out to improve the startability of the low-compression-ratio diesel engine.…”

Section: Introductionmentioning

confidence: 99%

Effect of the altitude on the combustion characteristics of a low-compression-ratio diesel engine during the start-up process

Kan

Lou

et al. 2016

Proceedings of the Institution of Mechanical Engineers, Part D:

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One of the ways to meet future emission standards for cars and to limit the peak pressure of a heavy-duty, highly supercharged diesel engine is to reduce the compression ratio. Nevertheless, complications appear because stringent limitations to a reduction in the diesel compression ratio are the start-up requirements, in particular at high altitudes. An experimental study was conducted on the effect of the altitude on the combustion characteristics during the start-up process of a direct-injection midspeed intercooled turbocharged diesel engine with a compression ratio of 14.25:1. Specialized testing was conducted on the low-compression-ratio diesel engine, the intake pressure and the exhaust pressure of which were controlled by a plateau simulation test system to simulate the conditions at altitudes of 0 m, 1000 m, 2000 m, 3000 m, 3750 m and 4500 m. The results indicated that the pressure in the cylinder was lower during the cranking period as the altitude increased and that this caused the ignition operation to become difficult at altitudes above 3000 m. The combustion characteristics are significantly impacted by altitudes above 2000 m. At an altitude of 0–1000 m, the curve pattern of the cycle cylinder pressure had mainly a single peak during the start-up period. When the altitude increased to 2000 m, twin peaks and afterburn appeared in the cycles. Misfire appeared during the start-up period when the altitude increased to 3000 m, the combustion instability increased and the average indicated mean effective pressure decreased rapidly. When the altitude increases, the cycle-to-cycle variations in the peak pressure increased during idle, the ignition and the crank angle position at 50% of the cumulative heat release rate were delayed and the combustion duration was extended.

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Analysis of Combustion Process in Cold Operation with a Low Compression Ratio Diesel Engine

Cited by 20 publications

References 17 publications

CFD Investigation on the Influence of In-Cylinder Mixture Distribution from Multiple Pilot Injections on Cold Idle Behaviour of a Light Duty Diesel Engine

CFD Investigation on the Influence of In-Cylinder Mixture Distribution from Multiple Pilot Injections on Cold Idle Behaviour of a Light Duty Diesel Engine

Ignition and combustion development for high speed direct injection diesel engines under low temperature cold start conditions

Effect of the altitude on the combustion characteristics of a low-compression-ratio diesel engine during the start-up process

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