Analysis of pre-ignition to super-knock: Hotspot-induced deflagration to detonation

Wang, Zhi; Qi, Yunliang; He, Xin; Wang, Jianxin; Shuai, Shijing; Law, Chung K.

doi:10.1016/j.fuel.2014.12.061

Cited by 184 publications

(61 citation statements)

References 14 publications

(17 reference statements)

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“…The deto-knock mechanism was first elucidated by Wang et al in 2015 [72] using synchronous high-speed direct photography and pressure measurements in a rapid compression machine (RCM). The results demonstrated that the mech- t=0.09ms…”

Section: Combustion Modes Associated With Deto-knockmentioning

confidence: 99%

Recent Progress in Automotive Gasoline Direct Injection Engine Technology

Shuai

et al. 2018

Automot. Innov.

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Gasoline direct injection (GDI) engines are currently the dominant powertrains for passenger cars. With the implementation of increasingly stringent fuel consumption and emission regulations worldwide, GDI engines are facing challenges owing to high particulate matter emissions and a tendency to knock, leading to a change in the research and design (R&D) issues compared with those in the twentieth century. This paper reviews the progress in research regarding GDI engine technologies over the past 20 years, focusing on combustion system configurations, and also highlights common issues in GDI R&D, including preignition and deto-knock, soot formation and PM emissions, injector deposits and gasoline compression ignition (GCI). First, an overview of recent developments in the field as driven by regulations is provided, following which progress in injection and combustion systems is examined. Third, the review addresses the occurrence and mechanism of deto-knock and considers means of suppressing this phenomenon. The fourth section discusses soot formation mechanisms and particulate matter emission characteristics of GDI engines and describes the application of gasoline particulate filter (GPF) after-treatment. The subsequent section summarizes studies regarding injector deposit formation, as well as pioneering research into GCI combustion modes. Finally, a summary and future prospects for GDI engine technologies are provided.

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Section: Combustion Modes Associated With Deto-knockmentioning

confidence: 99%

Recent Progress in Automotive Gasoline Direct Injection Engine Technology

Shuai

et al. 2018

Automot. Innov.

Self Cite

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“…It can lead to a very high peak pressure (~300 bar) and pressure oscillation (~100 bar), which could damage the cylinder or piston in one engine cycle. It is generally accepted that super-knock originates from pre-ignition and is accompanied by the phenomenon of detonation [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

“…Many experiments have been made in a rapid compression machine (RCM) [33][34][35] as well as in an optical engine withstanding high pressure [11,12] to prove that the autoignition and detonation phenomenon is present in the end region of the chamber when knock and super knock occurs. The resulting speeds of the detonation flame in the range of 1500-2300 m/s are close to Chapman-Jouget (CJ) velocity.…”

Section: Introductionmentioning

confidence: 99%

Different combustion modes caused by flame-shock interactions in a confined chamber with a perforated plate

Wei

Gao

Zhou

et al. 2017

Combustion and Flame

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“…Super knock usually happens before the spark ignition, which drives researchers to relate it to pre-ignition. Therefore, endeavors were made to dig the cause of pre-ignition [1][2][3][4]. On the other hand, although preignition is reckoned to be the indicator, it actually doesn't necessarily result in super knock.…”

Section: Introductionmentioning

confidence: 99%

Pressure Oscillations Generated by Knocking Combustion of C2H2 in a Constant Volume Vessel

Huang¹,

Huang²

2017

Proceedings of the 2016 4th International Conference on Renewable Energy and Environmental Technology (ICREET 2016)

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Abstract. Onset of super-knock in highly intensified spark ignition engines poses a great threat to the reliability. In this context, An approaching attempt was exerted on the initial condition of C 2 H 2 -O 2 -N 2 mixtures ignited within a constant volume vessel, in order to determine the critical condition of knock and response to oxygen ratio, acetylene ratio and mixture density. Results show that with a low acetylene content, sole elevation of oxygen doesn't necessarily lead to knock onset. On the other hand, with oxygen content fixed to a sufficient value, elevation of acetylene content results in louder combustion noise and when it approaches the stoichiometry ratio, auto-ignition happens in the unburnt far end and strong oscillation appears on the combustion pressure curve. Surprisingly, elevation of mixture density has no significant effect on knock propensity. IntroductionDownsizing is an effective strategy for gasoline engines to reduce fuel consumption and CO 2 emission. In the approach to downsizing, turbocharge and direct injection are commonly reckoned to be the most important techniques. However, application of them exerts a greater knock risk on the engines and moreover a new abnormal combustion phenomenon, namely super knock, which is even more devastating, stochastically occurs. Super knock usually happens before the spark ignition, which drives researchers to relate it to pre-ignition. Therefore, endeavors were made to dig the cause of pre-ignition [1][2][3][4]. On the other hand, although preignition is reckoned to be the indicator, it actually doesn't necessarily result in super knock. Regarding this, the transformation of deflagration to detonation is speculated by many researchers to be the key point.In this context, acetylene was ignited within a constant volume vessel for knock research due to its high knock tendency and gaseous nature convenient for mixture preparation. An approaching attempt was exerted on the initial condition of C 2 H 2 -O 2 -N 2 mixtures in order to determine the critical condition of knock and response to oxygen ratio, acetylene ratio and mixture density. During the experiment, pressure profile and combustion images were simultaneously recorded to observe pressure waves generated in the vessel.

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Analysis of pre-ignition to super-knock: Hotspot-induced deflagration to detonation

Cited by 184 publications

References 14 publications

Recent Progress in Automotive Gasoline Direct Injection Engine Technology

Recent Progress in Automotive Gasoline Direct Injection Engine Technology

Different combustion modes caused by flame-shock interactions in a confined chamber with a perforated plate

Pressure Oscillations Generated by Knocking Combustion of C2H2 in a Constant Volume Vessel

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