The Development and Evaluation of Robust Combustion Systems for Miller Cycle Engines

Ketterer, Justin E.; Gautier, Erwan; Keating, Edward J.

doi:10.4271/2018-01-1416

Cited by 4 publications

(1 citation statement)

References 27 publications

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“…Such results depend somewhat on the base combustion system of the engine where testing is performed. A large-scale project was undertaken by Ketterer et al [322] of GM studying EIVC and LIVC strategies with dedicated combustion systems for each. Here it was found that at peak power, the EIVC system had an advantage in terms of end of compression temperatures, and hence knocklimited combustion phasing, as it was more difficult to control the backflow of the LIVC concept at higher speeds.…”

Section: The 2010s: Aggressive Co 2 Targets Electrification and Downs...mentioning

confidence: 99%

Knock: A Century of Research

Corrigan¹,

Fontanesi²

2021

SAE Int. J. Engines

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Knock is one of the main limitations on increasing spark-ignition (SI) engine efficiency. This has been known for at least 100 years, and it is still the case today. Knock occurs when conditions ahead of the flame front in an SI engine result in one or more autoignition events in the end gas. The autoignition reaction rate is typically much higher than that of the flame-front propagation. This may lead to the creation of pressure waves in the combustion chamber and, hence, an undesirable noise that gives knock its name. The resulting increased mechanical and thermal loading on engine components may eventually lead to engine failure. Reducing the compression ratio lowers end-gas temperatures and pressures, reducing end-gas reactivity and, hence, mitigating knock. However, this has a detrimental effect on engine efficiency.Automotive companies must significantly reduce their fleet carbon dioxide (CO 2 ) values in the coming years to meet targets resulting from the 2015 Paris Agreement. One path towards meeting these is through partial or full electrification of the powertrain. However, the vast majority of automobiles in the near future will still feature a gasoline-fueled SI engine; hence, improvements in combustion engine efficiency remain fundamental.As knock has been a key limitation for so long, there is a huge amount of literature on the subject. A number of reviews on knock have already been published, including in recent years. These generally concentrate on current understanding and status. The present work, in contrast, aims to track the progress of research on knock from the 1920s right through to the present day. It is hoped that this can be a useful reference for new and existing researchers of the subject and give further weight to occasionally neglected historical activity, which can still provide important insights today.

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Section: The 2010s: Aggressive Co 2 Targets Electrification and Downs...mentioning

confidence: 99%

Knock: A Century of Research

Corrigan¹,

Fontanesi²

2021

SAE Int. J. Engines

View full text Add to dashboard Cite

show abstract

Effect of synergistic engine technologies for 48 V mild hybrid electric vehicles

Lee

Woo

et al. 2021

Energy Conversion and Management

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Lean-Stratified Combustion System with Miller Cycle for Downsized Boosted Application - Part 2

Battiston¹,

Wheeler²,

Solomon³

et al. 2021

SAE Int. J. Adv. & Curr. Prac. in Mobility

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<div class="section abstract"><div class="htmlview paragraph">Automotive manufacturers relentlessly explore engine technology combinations to achieve reduced fuel consumption under continued regulatory, societal and economic pressures. For example, technologies enabling advanced combustion modes, increased expansion to effective compression ratio and reduced parasitics continue to be developed and integrated within conventional and hybrid propulsion strategies across the industry. A high-efficiency gasoline engine capable for use in conventional or hybrid electric vehicle platforms is highly desirable. This paper is the second of two papers describing the multi-cylinder integration of a technology package combining lean-stratified combustion with Miller cycle for downsized boosted applications. The first paper describes the design, analysis and single-cylinder testing conducted to down-select the combustion system deployed to the multi-cylinder engine. This paper defines a light-duty engine package capable of achieving a 35% fuel economy improvement at US Tier 3 emission standards over a naturally aspirated stoichiometric baseline vehicle. A multi-mode combustion system was developed enabling highly efficient lean-stratified operation at light-load and stoichiometric Miller-cycle operation at mid- to high-loads. A central direct-injection four-valve layout was designed with high-tumble ports and a bowl-in-piston capable of stable operation under highly dilute mixtures when properly matched to fuel spray characteristics, injection strategy, and a high-energy ignition system. Boost system layout and base engine architecture were selected to minimize parasitics and maximize aftertreatment effectiveness. A multi-cylinder engine was developed and calibrated over a steady-state map. Results fed vehicle simulations over the EPA city and highway test cycles to predict the fuel economy improvement and tailpipe emissions potential. Fuel economy improvements over the baseline vehicle were projected at 42% and 39% for active-urea and passive-ammonia SCR aftertreatment systems respectively. Controls complexity to achieve regulatory compliance and the cost of the lean aftertreatment system were identified as the primary challenges to commercial viability.</div></div>

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The Development and Evaluation of Robust Combustion Systems for Miller Cycle Engines

Cited by 4 publications

References 27 publications

Knock: A Century of Research

Knock: A Century of Research

Effect of synergistic engine technologies for 48 V mild hybrid electric vehicles

Lean-Stratified Combustion System with Miller Cycle for Downsized Boosted Application - Part 2

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