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: liquidand 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.

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

Soot processes in compression ignition engines

Evaluating automobile fuel/propulsion system technologies

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 two-stage 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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Diesel combustion: an integrated view combining laser diagnostics, chemical kinetics, and empirical validation

Mobile sources critical review 1998 narsto assessment

Diesel Engines: One Option to Power Future Personal Transportation Vehicles

Quantitative Imaging Study of the Effects of Intake Air Temperature on Soot Evolution in an Optically-Accessible D.I. Diesel Engine

Dynamics of Multiple-Injection Fuel Sprays in a Small-bore HSDI Diesel Engine

An exhaust after-treatment system for a vehicle including a dosing agent that is selectively injected into an exhaust from a dosing agent supply includes a first module that determines a level of a dosing agent source. A second module selectively impedes vehicle operation by adjusting an engine operating mode if the level of said dosing agent source is below a threshold level.

Emissions conformance for an exhaust after-treatment system having a dosing agent supply

Energy availability, environmental impact, fuel price and legislation combined with shifts in customer buying preferences are driving significant interest in the development of fuel-efficient power train technologies. Advanced propulsion technologies are cri tical to developing sustainable transportation options for the future. The General Motors strategy for advanced powertrains involves multiple technologies to deliver the ex pected fuel economy and customer experience.

John A. Pinson

Papers

Diesel Engines: One Option to Power Future Personal Transportation Vehicles

Quantitative Imaging Study of the Effects of Intake Air Temperature on Soot Evolution in an Optically-Accessible D.I. Diesel Engine

Dynamics of Multiple-Injection Fuel Sprays in a Small-bore HSDI Diesel Engine

Emissions conformance for an exhaust after-treatment system having a dosing agent supply

What is the preferred powertrain of the future