Multi-Cylinder Laser and Spark Ignition in an IC Gasoline Automotive Engine: A Comparative Study

Mullett, Jack; Dickinson, Paul; Shenton, A.T.; Dearden, Geoff; Watkins, Ken

doi:10.4271/2008-01-0470

Cited by 17 publications

(9 citation statements)

References 18 publications

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“…The lack of an intruding electrode also reduces flame kernel quenching and results in shorter burn duration. In this context, the potential benefits of LI have been cited as: variation of ignition location in the cylinder [13]; no electrodes to disturb cylinder geometry or to quench a propagating flame kernel [14]; potential for engine control by varying ignition energy [15]; multiple ignition points in a cylinder [3,16]; lower energy needed for combustion [17]; more stable combustion and increased engine performance [18]; reduced tailpipe emissions [5]; combustion of leaner air-fuel mixtures [15,19]; shorter ignition delays and faster combustion [5] optical combustion sensing [12]. However, more experimental research is needed to build on the platform of fundamental LI science, to explore the potential benefits of LI applied to automotive IC engines from a perspective of enhanced combustion control.…”

Section: Potential Benefits Of LImentioning

confidence: 99%

“…2 and Figs. 3(a)-3(b) [18]. The variable pulse repetition rate (PRR) of the lasers gave additional 'redundant sparks' for self-cleaning of the optical plug window, as in Fig.…”

Section: Overview Of Key Findings From LI Research At Uolmentioning

confidence: 99%

“…Coating of this optical surface with combustion deposits ('sooting') has been a major drawback in attempts to demonstrate viability of LI in engines, since a build up of deposits with successive engine cycles degrades the transmission of laser energy. Despite this, several research groups have reported successful demonstration of LI, wherein an efficient 'self-cleaning' (SC) of the window surface by the pulsed laser radiation was observed [18,38,39], thus sustaining transmission through the optical pathway. Figure 2(c) shows an example of a window used in UoL work [18].…”

Section: Deployment Of Laser Energymentioning

confidence: 99%

See 2 more Smart Citations

Laser ignited engines: progress, challenges and prospects

Dearden

Shenton

2013

Opt. Express

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Laser ignition (LI) has been shown to offer many potential benefits compared to spark ignition (SI) for improving the performance of internal combustion (IC) engines. This paper outlines progress made in recent research on laser ignited IC engines, discusses the potential advantages and control opportunities and considers the challenges faced and prospects for its future implementation. An experimental research effort has been underway at the University of Liverpool (UoL) to extend the stratified speed/load operating region of the gasoline direct injection (GDI) engine through LI research, for which an overview of some of the approaches, testing and results to date are presented. These indicate how LI can be used to improve control of the engine for: leaner operation, reductions in emissions, lower idle speed and improved combustion stability.

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Section: Potential Benefits Of LImentioning

confidence: 99%

“…2 and Figs. 3(a)-3(b) [18]. The variable pulse repetition rate (PRR) of the lasers gave additional 'redundant sparks' for self-cleaning of the optical plug window, as in Fig.…”

Section: Overview Of Key Findings From LI Research At Uolmentioning

confidence: 99%

Section: Deployment Of Laser Energymentioning

confidence: 99%

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Laser ignited engines: progress, challenges and prospects

Dearden

Shenton

2013

Opt. Express

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“…Laser induced breakdown has been studied for a wide range of combustion applications including as an ignition source for reciprocating engines [1][2][3], gas turbines [4][5][6] and rocket engines [7,8], and as a means to provide flame stabilization in high speed diffusion jet flames [9][10][11][12]. For widely used nanosecond pulses, a typical breakdown event is governed by two processes.…”

Section: Introductionmentioning

confidence: 99%

Gas dynamics and vorticity generation in laser-induced breakdown of air

Dumitrache¹,

Yalin²

2020

Opt. Express

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Research has shown that the ignition characteristics of laser induced plasmas in fuel-air mixtures are influenced by the gas dynamics effects induced during the gas breakdown stage. Here, we present numerical modeling of the fluid mechanics induced by breakdown (plasma formation) from a nanosecond near-infrared (NIR) laser pulse in air. The simulations focus on the post-discharge kernel dynamics with the goal of developing a better understanding on how vorticity is generated during the kernel cooling phase. Initial conditions (ICs) of kernel shape, temperature and pressure (corresponding to the end of the laser pulse) are found from experimental Rayleigh scattering data. It is shown that this method for determining ICs is preferred versus use of the Taylor-Sedov blast wave theory as it provides a more accurate description of the starting field. Past experimental observations have revealed that the gas dynamics of nanosecond laser sparks typically lead to the formation of an asymmetric torus with a frontal lobe propagating towards the laser source. We show that the development of the asymmetric torus is governed by strong vorticity generated through baroclinic torque arising from the blast wave that forms at the kernel boundary. Initially, the blast takes the shape of the teardrop kernel but then evolves into a spherical front during the first ~10 µs because the blast wave strength varies along its circumference. This spatial variation leads to a misalignment between the pressure and density gradients and generation of vorticity by baroclinic torque. Ultimately, the observed flow-field is dictated by how the energy was initially deposited around the beam waist during breakdown. As such, one can tailor the aerodynamics induced during the cooling and recombination phase by controlling the energy deposition profile.

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“…LI was first employed to operate an engine (a one-cylinder ASTM-CFR engine) in 1978, by Dale et al 5 A large CO 2 laser with pulses having an energy of 0.3 J and 50 ns duration at 10.6 μm was used for the experiments. Furthermore, a real, four-cylinder Ford Mondeo engine was run via LI at Liverpool University in 2008, by Mullet et al 6 Here, electro-optically Q-switched Nd:YAG lasers with emission at 1.06 μm were employed. All these experiments were performed with commercial lasers that were positioned nearby the engine; typically, the laser beams were guided by mirrors and then focused inside the engine cylinder through a transparent window.…”

Section: Introductionmentioning

confidence: 99%

Assembly process and optical performances for a golden laser spark-plug device

et al. 2019

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The low-stress Solderjet Bumping technique was employed to assemble the optical components of an increased-robustness laser spark-plug ignition device using the low melting alloys 96.5Sn3Ag0.5Cu and 80Au20Sn. A finite-element-method analysis, optical simulations, and a soldering parametrization test were performed to prove that different optical materials (sapphire, ECO-550, D-ZLaF52LA, TAC4, and N-SF11 glasses) could be fastened to the stainless steel body. The assembled spark-plug device featured a passively Q-switched Nd∶YAG∕Cr 4þ ∶YAG composite ceramic medium and delivered laser pulses with energy variable between 2.40 and 4.70 mJ, with 0.8 ns duration, suitable for inducing air breakdown phenomenon and engine combustion. © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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Multi-Cylinder Laser and Spark Ignition in an IC Gasoline Automotive Engine: A Comparative Study

Cited by 17 publications

References 18 publications

Laser ignited engines: progress, challenges and prospects

Laser ignited engines: progress, challenges and prospects

Gas dynamics and vorticity generation in laser-induced breakdown of air

Assembly process and optical performances for a golden laser spark-plug device

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