skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Insights into engine autoignition: Combining engine thermodynamic trajectory and fuel ignition delay iso-contour

Journal Article · · Combustion and Flame
; ORCiD logo; ORCiD logo; ; ORCiD logo

One of the ultimate goals of chemical kinetic study is to understand and predict autoignition in engines. In this study, utilizing toluene primary reference fuels (TPRF) as a gasoline surrogate and a recently developed multicomponent gasoline kinetic mechanism, we have demonstrated a general approach to analyze autoignition in arbitrary spark-ignition (SI) and advanced compression ignition (ACI) engine conditions by combining thermodynamic pressure-temperature trajectory and the fuel ignition delay iso-contours. This method allows direct evaluation of controlling chemistry, potential involvement of low temperature heat release, and the dependence of autoignition to conventional fuel metrics (research and motor octane rating, i.e., RON and MON, and octane sensitivity OS = RON-MON) and engine operating conditions such as equivalence ratio, exhaust gas recirculation (EGR) ratio and engine intake conditions. Applying the analysis to the pressure-temperature trajectories of the conventional RON and MON tests, as well as those beyond RON and beyond MON, distinct roles of conventional gasoline fuel metrics and engine operating parameters are identified for all representative engine conditions. By comparing the autoignition behavior in ACI and SI engine conditions, the knowledge obtained from SI engine knock cannot be directly transferred to ACI bulk combustion phasing control in general, due to the different mixture equivalence ratios and the associated differences in reactivity and its dependence. Furthermore, this method could be extended to generate an auto-ignition map for arbitrary fuels and arbitrary engine trajectories, and the useful insights and overall evaluations can be used to complement conventional kinetic simulation of engine cycles.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Illinois at Chicago, IL (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
Grant/Contract Number:
AC05-00OR22725; EE0007985
OSTI ID:
1737851
Alternate ID(s):
OSTI ID: 1484991; OSTI ID: 1998756
Journal Information:
Combustion and Flame, Journal Name: Combustion and Flame Vol. 200 Journal Issue: C; ISSN 0010-2180
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 23 works
Citation information provided by
Web of Science

Figures / Tables (17)

Fig. 1(p. 3)figure Fig. 1
Table 1(p. 3)table Table 1
Fig. 2(p. 4)figure Fig. 2
Fig. 3(p. 4)figure Fig. 3
Fig. 4(p. 5)figure Fig. 4
Fig. 5(p. 5)figure Fig. 5
Fig. 6(p. 5)figure Fig. 6
Fig. 7(p. 6)figure Fig. 7
Fig. 8(p. 7)figure Fig. 8
Fig. 10(p. 8)figure Fig. 10
Fig. 9(p. 8)figure Fig. 9
Fig. 11(p. 9)figure Fig. 11
Fig. 12(p. 9)figure Fig. 12
Fig. A.1(p. 10)figure Fig. A.1
Fig. A.2(p. 10)figure Fig. A.2
Fig. A.3(p. 10)figure Fig. A.3
Fig. A.4(p. 11)figure Fig. A.4

Similar Records

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
Autoignition
Advanced compression ignition (ACI)
Octane rating
Octane sensitivity
Livengood-Wu method
Phi-sensitivity