What limits lean combustion: spark or propagation

Journal Article · Sat Jan 01 04:00:00 EST 1977 · Automot. Eng. (N.Y.); (United States)

OSTI ID:7319921

Many researchers have probed the limits of lean combustion in efforts to exploit the lower emissions and higher thermal efficiencies characterized by this operating mode. The advantages of high-energy ignition and ''just enough'' combustion chamber turbulence have been recurring themes in these investigations. Recent results from G. M. Research Laboratories suggest that the lean-mixture limit may, indeed, be an interplay of two distinct limiting factors. Under differing conditions of mixture strength and spark timing, two characteristic modes of combustion degradation were isolated: one traceable to problems of flame initiation and the other to poor propagation of the flame. A Cooperative Fuel Research (CFR) single-cylinder engine, fueled by bottled propane and operated under steady-state conditions was used. Both the standard capacitive discharge unit and a programmable high-energy ignition system were employed during the investigation. Suitable devices were used to monitor engine input and output, among the latter CO, CO/sub 2/, HC, NO/sub x/ and oxygen.

• OSTI ID: 7319921
• Journal Information: Automot. Eng. (N.Y.); (United States), Journal Name: Automot. Eng. (N.Y.); (United States) Vol. 85:1; ISSN AUEGB
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330101* -- Internal Combustion Engines-- Spark-Ignition
330704 -- Emission Control-- Hydrocarbons
ENGINES
EXHAUST GASES
FLAMES
FUEL SYSTEMS
FUEL-AIR RATIO
GAS COMBUSTION PROCESS
GASEOUS WASTES
HYDROCARBONS
IGNITION
INTERNAL COMBUSTION ENGINES
ORGANIC COMPOUNDS
SPARK IGNITION ENGINES
TIME DEPENDENCE
WASTES