Ignition characteristics of rich N-heptane fuel sprays in the transition region

Conference · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5717276

Danis, A M; Cernansky, N P; Namer, I

Ignition studies were performed on monodisperse n-heptane sprays at atmospheric pressure over a range of equivalence ratios and droplet diameters. A capacitive discharge spark ignition system was used as the ignitions source, providing independent control of spark energy and duration. Preliminary measurements were made to optimize spark duration and spark gap, optimum conditions being those at which the maximum frequency or probability of ignition was observed. Using the optimum electrode spacing and and spark duration, the frequency of ignition was determined as a function of spark energy for three overall equivalence ratios (0.6, 0.8, and 1.0) and the initial droplet diameters of 25, 40, 50, 60, and 70 ..mu..m. An LDA system was used to determine the actual equivalence ratio at the spark gap, which varied from 1.5 to 4.7. The spark energy at which the frequency of ignition was 90 percent was defined as the minimum ignition energy. These data indicated that the ignitability of the sprays was enhanced as the equivalence ratio was increased, but was diminished as the droplet size was increased. The increase in minimum ignition energy with increasing droplet size and fixed equivalence ratio was nearly linear over the range of parameters studied. However, the effect became smaller with increasing equivalence ratio.

• OSTI ID: 5717276
• Report Number(s): CONF-851125-
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
025000* -- Petroleum-- Combustion
33 ADVANCED PROPULSION SYSTEMS
330101 -- Internal Combustion Engines-- Spark-Ignition
330800 -- Emission Control-- Alternative Fuels
ABSTRACTS
ALKANES
ATMOSPHERIC PRESSURE
BENCH-SCALE EXPERIMENTS
CHEMICAL REACTIONS
COMBUSTION
COMBUSTION PROPERTIES
COMPARATIVE EVALUATIONS
DOCUMENT TYPES
DROPLETS
ENGINES
FUEL SUBSTITUTION
HEAT ENGINES
HEPTANE
HYDROCARBONS
IGNITION
IGNITION QUALITY
IGNITION SYSTEMS
INTERNAL COMBUSTION ENGINES
LEADING ABSTRACT
MEETINGS
OPTIMIZATION
ORGANIC COMPOUNDS
OXIDATION
PARTICLE SIZE
PARTICLES
PROBABILITY
SIZE
SPARK GAPS
SPARK IGNITION ENGINES
SPRAYS
THERMOCHEMICAL PROCESSES