A simple model for cyclic variations in a spark-ignition engine

Conference · Wed May 01 04:00:00 EDT 1996

OSTI ID:220572

Daw, C S; Green, Jr, J B; Kennel, M B; Thomas, J F ^[1]; Finney, C E.A. ^[2]; Connolly, F T ^[3]

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1. Oak Ridge National Lab., TN (United States)
2. Univ. of Tennessee, Knoxville, TN (United States)
3. Ford Motor Co., Dearborn,, MI (United States)

We propose a simple model that explains important characteristics of cyclic combustion variations in spark-ignited engines. A key model feature is the interaction between stochastic, small-scale fluctuations in engine parameters and nonlinear deterministic coupling between successive engine cycles. Prior-cycle effects are produced by residual cylinder gas which alters mean in-cylinder equivalence ratio and subsequent combustion efficiency. The model`s simplicity allows rapid simulation of thousands of engine cycles, permitting in-depth statistical studies. Additional mechanisms for stochastic and prior-cycle effects can be added to evaluate their impact on overall engine performance. We find good agreement with experimental data.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-96OR22464
• OSTI ID: 220572
• Report Number(s): CONF-9605160--1; ON: DE96009409
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
COMBUSTION
PERFORMANCE
SPARK IGNITION ENGINES