Planar Laser Light Scattering for the In-Cylinder Study of Soot in a Diesel Engine

Lee, Wonnam; Solbrig, Charles E.; Litzinger, Thomas A.; Santoro, Robert J.

doi:10.4271/902125

Cited by 16 publications

(3 citation statements)

References 18 publications

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“…These diagnostics allow specific species within the reacting jet to be measured at multiple points simultaneously (planar imaging) with high spatial and temporal resolution, and many of these techniques can be designed to yield semi-quantitative and even fully quantitative data. Over the past eight years, laser diagnostics have been applied to directinjection (DI) diesel combustion in a variety of optically accessible engines [9][10][11][12][13][14][15][16][17][18][19][20] as well as to "diesel-like" combustion in rapid compression machines [21][22][23] and diesel simulation vessels [24][25][26][27][28] that were also fitted with windows. These investigations have provided an abundance of new information on diesel combustion that, to a large extent, has not supported the earlier description of diesel combustion.…”

Section: Introductionmentioning

confidence: 99%

A Conceptual Model of DI Diesel Combustion Based on Laser-Sheet Imaging*

Dec¹

1997

SAE Technical Paper Series

1,025

584

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A phenomenological description, or "conceptual model," of how direct-injection (DI) diesel combustion occurs has been derived from laser-sheet imaging and other recent optical data. To provide background, the most relevant of the recent imaging data of the author and co-workers are presented and discussed, as are the relationships between the various imaging measurements. Where appropriate, other supporting data from the literature is also discussed. Then, this combined information is summarized in a series of idealized schematics that depict the combustion process for a typical, modern-diesel-engine condition. The schematics incorporate virtually all of the information provided by our recent imaging data including: liquid-and vapor-fuel zones, fuel/air mixing, autoignition, reaction zones, and soot distributions. By combining all these elements, the schematics show the evolution of a reacting diesel fuel jet from the start of fuel injection up through the first part of the mixing-controlled burn (i.e. until the end of fuel injection). In addition, for a "developed" reacting diesel fuel jet during the mixingcontrolled burn, the schematics explain the sequence of events that occurs as fuel moves from the injector downstream through the mixing, combustion, and emissions-formation processes. The conceptual model depicted in these schematics also gives insight into the most likely mechanisms for soot formation and destruction and NO formation during the portion of the DI diesel combustion event discussed.

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Section: Introductionmentioning

confidence: 99%

A Conceptual Model of DI Diesel Combustion Based on Laser-Sheet Imaging*

Dec¹

1997

SAE Technical Paper Series

1,025

584

View full text Add to dashboard Cite

show abstract

“…Government laboratories in the U.S., Europe and several universities (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) have undertaken laser imaging studies to define the structure of diesel flames and their temporal evolution. Although these diagnostics were performed on a variety of engine and high-pressure vessel configurations, they show many similarities and begin to form a basis for the general description of a burning diesel fuel spray plume.…”

mentioning

confidence: 99%

Diesel Combustion: An Integrated View Combining Laser Diagnostics, Chemical Kinetics, And Empirical Validation

Flynn

Durrett

Hunter

et al. 1999

SAE Technical Paper Series

323

201

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February 1999This is a preprint of a paper intended for publication in a journal or proceedings. Since changes may be made before publication, this preprint is made available with the understanding that it will not be cited or reproduced without the permission of the author. PREPRINTThis paper was prepared for submittal to the DISCLAIMER This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product endorsement purposes. 1999-01- Charles K. WestbrookLawrence Livermore National Laboratory ABSTRACT This paper proposes a structure for the diesel combustion process based on a combination of previously published and new results. Processes are analyzed with proven chemical kinetic models and validated with data from production-like direct injection diesel engines. The analysis provides new insight into the ignition and particulate formation processes, which combined with laser diagnostics, delineates the twostage nature of combustion in diesel engines. Data are presented to quantify events occurring during the ignition and initial combustion processes that form soot precursors.A framework is also proposed for understanding the heat release and emission formation processes.

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“…Several optical techniques can be used for in-cylinder soot concentration measurements. Two-dimensional imaging of the soot distributions has been obtained by light scattering [30] or laser-induced incandescence (LII) [31], which require expensive laser and optical equipment and extensive engine modi®cations. These measurements are limited to one measurement per cycle, owing to the limited frequency of the laser and detector.…”

Section: In-cylinder Soot Concentration Measurement By the Light Extinction Methodsmentioning

confidence: 99%

In-cylinder studies of the effects of CO₂ in exhaust gas recirculation on diesel combustion and emissions

Zhao

Ladommatos

2000

Proceedings of the Institution of Mechanical Engineers, Part D:

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This paper reports the results of the effects of CO2 in exhaust gas recirculation (EGR) on diesel combustion and emissions. The experiments were carried out on a specially designed single-cylinder diesel engine. In-cylinder measurements were obtained from the optically accessible swirl chamber using high-speed shadowgraphy, the two-colour method and laser extinction. Furthermore, in-cylinder pressure measurements from the combustion chambers were used to derive the heat release rates during combustion. Two experiments were carried out on the effects of CO2 on diesel combustion and pollutant formation. In the first series of experiments, CO2 was used to replace some of the oxygen in the intake mixture, which simulated the dilution effect of conventional EGR. This so-called replacement EGR method was characterized by the typical NOx and smoke trade-off, where NOx reduction was accomplished at the expense of exhaust smoke. In the second series of tests, CO2 was added to the intake charge so that the oxygen concentration in the combustion chamber was not affected. In this additional EGR method, CO2 was found to suppress both NOx and smoke emissions. The mechanisms of these two different EGR modes on diesel combustion and emissions were examined using the above in-cylinder measurement techniques and exhaust emission analysis.

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Planar Laser Light Scattering for the In-Cylinder Study of Soot in a Diesel Engine

Cited by 16 publications

References 18 publications

A Conceptual Model of DI Diesel Combustion Based on Laser-Sheet Imaging*

A Conceptual Model of DI Diesel Combustion Based on Laser-Sheet Imaging*

Diesel Combustion: An Integrated View Combining Laser Diagnostics, Chemical Kinetics, And Empirical Validation

In-cylinder studies of the effects of CO₂ in exhaust gas recirculation on diesel combustion and emissions

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Planar Laser Light Scattering for the In-Cylinder Study of Soot in a Diesel Engine

Cited by 16 publications

References 18 publications

A Conceptual Model of DI Diesel Combustion Based on Laser-Sheet Imaging*

A Conceptual Model of DI Diesel Combustion Based on Laser-Sheet Imaging*

Diesel Combustion: An Integrated View Combining Laser Diagnostics, Chemical Kinetics, And Empirical Validation

In-cylinder studies of the effects of CO2 in exhaust gas recirculation on diesel combustion and emissions

Contact Info

Product

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In-cylinder studies of the effects of CO₂ in exhaust gas recirculation on diesel combustion and emissions