Laser ignited engines: progress, challenges and prospects

Dearden, Geoff; Shenton, Tom

doi:10.1364/oe.21.0a1113

Cited by 61 publications

(17 citation statements)

References 36 publications

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“…The findings based on Figure 6 indicate that it is possible to obtain successful ignition and self-sustained combustion even for the fuel-lean cases by judicious choice of R, b sp , a sp and these parameters can be altered independently of each other in case of laser ignition. The present findings are consistent with recent experimental findings [8,[27][28][29][30][39][40][41] that laser ignition can be effective in igniting fuel-lean mixtures by altering the laser power (i.e. equivalent to the variation of a sp ), laser beam radius (i.e.…”

Section: Ignition and Self-sustained Combustion For Fuel-lean Mixturessupporting

confidence: 93%

Effects of Energy Deposition Characteristics on Localised Forced Ignition of Homogeneous Mixtures

Patel

Chakraborty

2015

International Journal of Spray and Combustion Dynamics

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The effects of the characteristic width of the energy deposition profile and the duration of energy deposition by the ignitor on localised forced ignition of stoichiometric and fuel-lean homogeneous mixtures have been analysed using simplified chemistry three-dimensional compressible Direct Numerical Simulation (DNS) for different values of root-mean-square turbulent velocity fluctuation. The localised forced ignition is modelled using a source term in the energy transport equation, which deposits energy in a Gaussian manner from the centre of the ignitor over a stipulated period of time. It has been shown that the width of ignition energy deposition and the duration over which ignition energy is deposited have significant influences on the success of ignition and subsequent flame propagation. An increase in the width of ignition energy deposition (duration of energy deposition) for a given amount of ignition energy has been found to have a detrimental effect on the ignition event, which may ultimately lead to misfire. Moreover, an increase in uЈ gives rise to augmented heat transfer rate from the hot gas kernel, which in turn leads to a reduction in the extent of overall burning for both stoichiometric and fuel-lean homogeneous mixtures but the detrimental effects of high values of uЈ on localised ignition are particularly prevalent for fuel-lean mixtures.

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Section: Ignition and Self-sustained Combustion For Fuel-lean Mixturessupporting

confidence: 93%

Effects of Energy Deposition Characteristics on Localised Forced Ignition of Homogeneous Mixtures

Patel

Chakraborty

2015

International Journal of Spray and Combustion Dynamics

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“…An explanation for this is that increasing the energy had a limited effect on the beam pulse duration. Furthermore, since the breakdown threshold intensity for a given gas is constant, the effect of increasing laser energy acts only to achieve this breakdown prior to the desired focal position (minimum beam waist) (Dearden and Shenton, 2013). Thus, increasing the laser energy may have an adverse effect of bringing the plasma location closer to the cylinder wall (Dearden and Shenton, 2013).…”

Section: Impact Of Ignition Energies On the Pressure Rise Ratementioning

confidence: 99%

Characterization of gasoline combustion with laser and spark ignition

Fang

Luo

et al. 2015

J. Zhejiang Univ. Sci. A

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Abstract:The combustion of gasoline-air mixtures in a constant-volume combustion chamber with an initial condition of 0.1 MPa pressure and 363 K temperature is experimentally investigated with laser ignition generated by a Q-switched Nd:YAG laser (wavelengths of 532 and 1064 nm). Spark ignition is also tested, and the results are used as the benchmark. Combustion chamber pressure is measured by a piezoelectric pressure transducer, and recorded using a digital oscilloscope. When the equivalence ratio is swept from 1.2 to 1.8, laser and spark ignition show marginal differences in pressure rise rate and peak pressure. The maximum pressure rise rate and the maximum peak pressure are obtained at equivalence ratios of 1.6 and 1.8 for laser ignition and spark ignition, which are 39.4 MPa/μs and 0.68 MPa for the laser wavelength of 532 nm, 38.8 MPa/μs and 0.67 MPa for the laser wavelength of 1064 nm, and 38.1 MPa/μs and 0.67 MPa for spark ignition, respectively. When the equivalence ratio is reduced below 1.2, the pressure rise rate and peak pressure of the laser ignition are significantly higher than those of spark ignition, and the lean limit for laser ignition is also wider than that of spark ignition; therefore, laser ignition is more favorable for lean combustion. For both the laser and spark ignitions, the ignition energy demonstrated a limited impact on both the pressure rise rate and peak pressure. Heat release rate in the combustion chamber is calculated, and the results show that variations of heat release are in accordance with variations of the pressure history.

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“…The essential stage for processes of non-resonant breakdown (NRB) and resonant breakdown (RB) is the non-resonant photo-dissociation of a molecules (NRPD) by absorption and ionization. The non-resonant breakdown is a laser ignition mechanism that produces and emits light, heat and a shockwave, [5,6]. The photo-chemical ignition (PCI) is a process that requires the absorption and dissociation of a single photon in ultraviolet radiation [5,6].…”

Section: Introductionmentioning

confidence: 99%

Aspects of experimental investigations of laser plug ignition use at spark ignition engine

Done

2017

MATEC Web Conf.

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Abstract. Nowadays, the necessity of pollutant emissions reduction brings to the fore new technologies developed for a better control of the combustion process. Ignition is the process of starting radical reactions until a selfsustaining flame has developed and strongly affects the formation of pollutants. Among the new technologies used for ignition and combustion control, the Laser Plug Ignition system is defined as an innovative technology which overcomes several limitations of conventional spark ignition. Laser ignition technology presents many advantages for engine operating control, engine performance improvement and pollutant emissions reduction. The objective of the paper is the experimental research of the laser ignition used in the spark ignition engine. The laser plug ignition system was mounted on an experimental spark ignition engine and tested at the regime of 90% load and 2800 rpm and dosage, =1. The experimental results present the influence of laser ignition on different engine parameters compared to electric spark ignition. The influence on in-cylinder pressure, heat release rate, engine efficiency and pollutant emissions level is analyzed. Compared to a conventional spark plug, a laser ignition system assures efficient engine operation at lean dosages.

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Laser ignited engines: progress, challenges and prospects

Cited by 61 publications

References 36 publications

Effects of Energy Deposition Characteristics on Localised Forced Ignition of Homogeneous Mixtures

Effects of Energy Deposition Characteristics on Localised Forced Ignition of Homogeneous Mixtures

Characterization of gasoline combustion with laser and spark ignition

Aspects of experimental investigations of laser plug ignition use at spark ignition engine

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