Estimation of Combustion Variability Using In-cylinder Ionization Measurements
2001-01-3485
09/24/2001
- Event
- Content
- This paper investigates the use of the ionization current to estimate the Coefficient of Variation for the Indicated Mean Effective Pressure, COV(IMEP), which is a common variable for combustion stability in a spark ignited engine. Stable combustion in this definition implies that the variance of the produced work, measured over a number of consecutive combustion cycles, is small compared to the mean of the produced work. The COV(IMEP) is varied experimentally either by increasing EGR flow or by changing the air-fuel ratio, in both a laboratory setting (engine in dynamometer) and in an on-road setting. The experiments show a positive correlation between COV(Ion integral), the Coefficient of Variation for the integrated Ion Current, and COV(IMEP), when measured under low load on an engine in a dynamometer, but not under high load conditions. On-road experiments show a positive correlation, but only in the EGR and the lean burn case. An approach based on individual cycle classification for real time estimation of combustion stability is discussed.
- Pages
- 8
- Citation
- Byttner, S., Rögnvaldsson, T., and Wickström, N., "Estimation of Combustion Variability Using In-cylinder Ionization Measurements," SAE Technical Paper 2001-01-3485, 2001, https://doi.org/10.4271/2001-01-3485.