Spray and flame structure in diesel combustion

Journal Article · Sat Jul 01 00:00:00 EDT 1989 · Journal of Engineering for Gas Turbines and Power; (USA)

DOI:https://doi.org/10.1115/1.3240275· OSTI ID:7174012

Balles, E N ^[1]; Heywood, J B ^[2]

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1. Arthur D. Little, Inc., Cambridge, MA (US)
2. Sloan Automotive Lab., Massachusetts Institute of Technology. Cambridge, MA (US)

The diesel combustion process in direct-injection diesel engines consists of four distinct stages: an ignition delay, a premixed phase, a mixing-controlled phase, and a late combustion phase. This paper uses geometric information form high-speed direct and shadowgraph movies and corresponding combustion chamber pressure histories, taken in a rapid compression machine study of direct-injection diesel combustion, for a coupled analysis of the diesel flame geometry and energy or heat release to develop our understanding of the diesel spray and flame structure during the ignition delay period and premixed combustion phase. It is shown that each fuel spray from a multihole fuel-injector nozzle consists of a narrow liquid-containing core centered within a much larger fuel-vapor air region, which has a distinct boundary. The liquid core does not penetrate to the chamber periphery, while the vapor containing spray interacts strongly with the boundary. Ignition occurs part way along each growing spray. Once combustion starts, the outer boundary of the fuel-vapor-containing region expands more rapidly due to the combustion energy release. Very high initial spreading rates of the luminous region boundary are observed. A comparison of enflamed areas and volumes, and burned gas volumes, indicates that the luminous region during the early stages of combustion (assumed stoichiometric) is around 1 cm thick and does not fill the full height of the chamber.

• OSTI ID: 7174012
• Journal Information: Journal of Engineering for Gas Turbines and Power; (USA), Journal Name: Journal of Engineering for Gas Turbines and Power; (USA) Vol. 111:3; ISSN JETPE; ISSN 0742-4795
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330102* -- Internal Combustion Engines-- Diesel
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800 -- Combustion
Pyrolysis
& High-Temperature Chemistry
CHEMICAL REACTIONS
COMBUSTION
COMBUSTION CHAMBERS
DIESEL ENGINES
DIESEL FUELS
ENGINES
FLAME PROPAGATION
FUEL INJECTION SYSTEMS
FUEL SYSTEMS
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
OXIDATION
PETROLEUM PRODUCTS
PRESSURE GRADIENTS
THERMOCHEMICAL PROCESSES