Relative roles of premixed and diffusion burning in diesel combustion

Journal Article · Sat Oct 01 04:00:00 EDT 1983 · SAE Spec. Publ.; (United States)

DOI:https://doi.org/10.4271/831733· OSTI ID:6552935

Plee, S L; Ahmad, T

Relative roles of premixed and diffusion burning in diesel combustion have been examined in terms of characteristic times for ignition delay (/tau/ /SUB ig/), combustion (/tau/ /SUB c/) and fuel-air mixing (/tau/ /SUB m/). Results indicate that the majority of the diesel combustion process is diffusion controlled, as in gas turbine combustion, since /tau/ /SUB c/ << /tau/ /SUB m/ over the entire range of operating conditions. During the ignition phase, some premixed burning can occur in the fringe of the fuel spray where /tau/ /SUB m/ < /tau/ /SUB ig/; however, most of the fuel injected prior to ignition also burns in the diffusion mode, since /tau/ /SUB m/ > /tau/ /SUB ig/ in the majority of the fuel spray. The fraction of premixed burning which occurs during the ignition phase is increased by longer /tau/ /SUB ig/, high rates of fuel injection, high air swirl and the use of multi-hole injectors, which increase the surface area of the spray.

• Research Organization: General Motors Research Laboratories
• OSTI ID: 6552935
• Journal Information: SAE Spec. Publ.; (United States), Journal Name: SAE Spec. Publ.; (United States) Vol. SP-557; ISSN SAESA
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330102* -- Internal Combustion Engines-- Diesel
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COMBUSTION
COMBUSTION KINETICS
DIESEL ENGINES
ENGINES
FUEL INJECTION SYSTEMS
FUEL SYSTEMS
FUEL-AIR RATIO
HEAT ENGINES
IGNITION
INTERNAL COMBUSTION ENGINES
KINETICS
OXIDATION
REACTION KINETICS
THERMOCHEMICAL PROCESSES