Prediction of ignition delay and combustion intervals for a homogeneous charge, spark ignition engine

Conference · Sun Jan 01 04:00:00 EST 1978

OSTI ID:6536098

Hires, S D; Tabaczynski, R J; Novak, J M

Correlations for the ignition delay and combustion energy release intervals in a homogeneous charge, spark-ignited engine are developed. After incorporation within a simplified engine cycle simulation, predicted values of these two combustion parameters are compared to experimental engine data. The correlations are based on four fundamental quantities--the turbulent integral scale, the turbulent micro-scale, the turbulent intensity, and the laminar flame speed. The major assumptions include: (1) the turbulent integral scale is proportional to the instantaneous chamber height prior to flame initiation; (2) angular momentum is conserved in the individual turbulent eddies ahead of the flame front (i.e., a ''rapid distortion'' turbulence model); and (3) the turbulent intensity scales with the mean piston speed. Two empirical constants scale the correlations to a given engine. Predicted values for the ignition delay and burn intervals show good agreement with experimental results for wide variations in engine operating and design conditions (e.g., engine speed and load, spark timing, EGR, air-fuel ratio, and compression ratio). In addition, the shapes of the predicted mass fraction burned curves agree well with published data.

• OSTI ID: 6536098
• Report Number(s): CONF-780208-69
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330101* -- Internal Combustion Engines-- Spark-Ignition
AUTOMOBILES
ENGINES
EXHAUST GASES
GASEOUS WASTES
IGNITION SYSTEMS
INTERNAL COMBUSTION ENGINES
MATHEMATICAL MODELS
PERFORMANCE
SPARK IGNITION ENGINES
THERMODYNAMICS
VEHICLES
WASTES